Holosun IRIS 3 vs IRIS 4: which multi-laser device should you buy?
Our verdict: the lasers and the IR illuminator are rated the same on both, so the choice comes down to one question: do you want a white light built in? Buy the IRIS 4 (around $1,000, green laser version IRIS-GR4) if you want a single unit that also replaces your weapon light: it adds a 1,000 lumen, 25,000 candela white light and takes an 18650 or two CR123A cells. Buy the IRIS 3 (around $900, green laser version IRIS-GR3) if you already run a separate weapon light or want the smaller, lighter unit: 6.4 oz against 8.5 oz, one CR123A, and a simpler one-button body. For a higher-end device built for military and police use, see our Wilcox RAID Xe review.
OpticsPlanet shoppers rate the IRIS 3 4.8/5 (8 reviews) and the IRIS 4 4.9/5 (10 reviews), small samples on both. Check price and availability on OpticsPlanet; confirm the current price on the retailer page.
How this comparison was made: a research-based, spec-by-spec comparison built from Holosun's own product pages for the IRIS-GR3, IRIS-GR4, IRIS-RD3 and IRIS-RD4, the OpticsPlanet listings, and every OpticsPlanet review we could read (8 for the IRIS 3, 10 for the IRIS 4). We have not bench-tested either unit; verdicts are our editorial opinion, and owner ratings are shown attributed to their source. See how we evaluate.
What these devices are
The IRIS 3 and IRIS 4 are rifle-mounted multi-function laser aiming devices, not sights and not simply weapon lights. Each puts a visible aiming laser, an infrared (IR) aiming laser and an IR illuminator in one Picatinny-mounted housing; the IRIS 4 adds a white light as a fourth function, which is where the "Triple Function" and "Quad Function" names come from. Holosun describes the visible laser as a daylight aiming point and says the IR aiming laser is for use with night vision devices; reviewers on both listings mention night vision use.
Side-by-side specifications
| IRIS 3 (IRIS-GR3) | IRIS 4 (IRIS-GR4) | |
|---|---|---|
| Street price | around $900 | around $1,000 |
| Owner rating | 4.8/5, 8 reviews on OpticsPlanet | 4.9/5, 10 reviews on OpticsPlanet |
| Functions | Visible laser, IR laser, IR illuminator | Visible laser, IR laser, IR illuminator, white light |
| White light | None | 1,000 lumens, 25,000 candela |
| IR illuminator | 60 mW VCSEL | 60 mW VCSEL |
| IR beam adjustment | Top-mounted slider, wide flood to tight spot | Top-mounted slider, wide flood to tight spot |
| Visible laser | Under 5 mW, Class 3R; green 520 nm or red 635 nm | Under 5 mW, Class 3R; green 520 nm or red 635 nm |
| IR laser | Under 0.7 mW, Class 1, 800 to 880 nm | Under 0.7 mW, Class 1, 800 to 880 nm |
| Battery | 1x CR123A (front cap access) | 1x 18650 or 2x CR123A |
| On-unit controls | Center ambidextrous fire button, momentary or constant on | Independent fire buttons, rear power selector |
| Remote switch included | Low-profile dual-button Crane plug pressure pad, VIS override | Three-button Crane plug pressure pad, dual lead, VIS override |
| Laser adjustment | Not listed on the maker page | 0.5 MOA per click, +/-50 MOA travel |
| Dimensions | 3.2 x 1.97 x 1.34 in | 4.2 x 2.3 x 1.4 in |
| Weight | 6.4 oz | 8.5 oz |
| Housing | 7075-T6 aluminum, anodized | 7075-T6 aluminum, hard anodized |
| Water rating | IPX8 | IPX8 |
| Vibration rating | 1000G | 1000G |
| Operating temperature | -30 to 51 C | -30 to 51 C |
| Mount | Picatinny, direct | Picatinny, direct |
| Check IRIS 3 price | Check IRIS 4 price |
Specifications from Holosun's product pages. The OpticsPlanet spec table lists the IRIS 4 battery as CR123A only; Holosun lists 1x 18650 or 2x CR123A, and we follow the manufacturer. Holosun's IRIS 3 page does not list a laser adjustment value, so we leave that cell open rather than assume it matches.
The white light: the whole case for the IRIS 4
The IRIS 4's headline addition is a 1,000 lumen, 25,000 candela white light in the same housing as the lasers and the IR illuminator, and it is the feature its reviewers single out. One verified owner writes that it "eliminates the need for a stand along light option in my opinion," another says "I like this better than a separate floodlight," and a third calls the light and the laser bright. If your rifle does not have a weapon light yet, the IRIS 4 covers both jobs with one mount and one remote pad.
The cost of that light is size and weight. Holosun lists the IRIS 4 at 4.2 x 2.3 x 1.4 in and 8.5 oz against the IRIS 3's 3.2 x 1.97 x 1.34 in and 6.4 oz, a full inch more on the largest dimension and about a third heavier. It also changes the power source: the IRIS 4 takes one 18650 or two CR123A cells, where the IRIS 3 runs on one CR123A.
Where the IRIS 3 wins: size, weight and simplicity
If you already have a weapon light you trust, the IRIS 4's white light is weight you carry twice. The IRIS 3 keeps the same rated visible laser, IR laser and 60 mW VCSEL illuminator in the smaller, lighter body. Reviewers notice: the IRIS 3 listing's reviews praise its small size and light weight, and one verified owner found it "Easy to co-align with red dot sight." Holosun gives it a single center-positioned, ambidextrous fire button for momentary or constant on, a low-profile dual-button remote pad, and a front battery cap for changing the CR123A in the field.
Price is the other point. The IRIS 3 costs less, and value is the most common theme in its reviews: at least five of the eight reviews we could read bring up price or value.
Controls and the remote pressure pad
Both units ship with a Crane plug remote pressure pad with a visible laser override (VIS override), which Holosun lists on both product pages. The IRIS 3's pad is a low-profile dual-button design. The IRIS 4 gets a three-button pad with a dual lead, plus independent fire buttons and a rear power selector on the body. Two IRIS 4 reviewers flag trade-offs here: one lists the "Dual cables for pressure pad" as a con, and another notes they "can not change back pad button, always set to visible laser and light." A third calls the VIS override phenomenal.
What is the same: lasers, illuminator and build
Holosun rates the aiming side identically. The visible laser is under 5 mW and Class 3R, at 520 nm on the green versions and 635 nm on the red versions; the IR laser is under 0.7 mW, Class 1, 800 to 880 nm; the IR illuminator is a 60 mW VCSEL with a top-mounted slider to adjust the beam. Both housings are 7075-T6 aluminum, rated IPX8, 1000G vibration and -30 to 51 C, and both mount directly to Picatinny. In short, the IRIS 4 is not a stronger laser; it is the IRIS 3's aiming package plus a white light in a bigger body.
What owners flag on each
Both review pools are small (8 and 10) and recent, so treat these as individual reports, not patterns.
IRIS 3 (8 reviews on OpticsPlanet: six 5-star, two 4-star)
- Front sight blocks: one verified owner warns that on a rifle with a front sight block "the illuminator will be cut in half and you'll have to take it off to swap out your battery". They list "hard to tie down" as a con and run it on free-float handguards.
- Narrow illuminator: one reviewer writes "I have ordered a diffuser to open up the illuminator."
- Water resistance: Holosun rates it IPX8, but one verified owner lists "Not so sure how waterproof the unit is" as a con; that is a doubt, not a test result.
IRIS 4 (10 reviews on OpticsPlanet: nine 5-star, one 4-star)
- Visible laser in daylight: one verified owner writes "I'm able to see it in daytime light (Arizona in May) out to 100 yards."
- Illuminator focus: the same owner found "Night illumination is decent but focused" and picked up a diffuser to broaden it, the same fix one IRIS 3 reviewer reached for.
- Holding zero: one verified owner reports "about 500 rounds with zero still solid."
- Mounting screw: one verified owner says the mounting screw is too long: "Once you torque it down to their specs it sticks out past the unit near 1/4 inch!"
- Price: one verified owner's only listed con is "Not cheap."
Which one should you buy?
- You have no weapon light on the rifle yet: IRIS 4. The built-in 1,000 lumen light saves a second mount and switch.
- You already run a weapon light you like: IRIS 3. Same rated lasers and illuminator, 2.1 oz lighter and a full inch smaller on the largest dimension.
- You want 18650 power: IRIS 4, which takes an 18650 or two CR123A cells. The IRIS 3 is CR123A only.
- Lower cost of the two: IRIS 3.
- Green or red: both models come in green (GR) and red (RD) versions at the same price as their sibling, so pick the color you prefer without a price penalty.
Holosun also makes smaller members of the family: OpticsPlanet lists an IRIS 1 (single function) and an IRIS 2 (visible plus IR laser). We have not reviewed those here.
FAQ
Holosun IRIS 3 or IRIS 4: which should I buy?
Buy the IRIS 4 if you want one unit to replace both your laser device and your weapon light: it adds a 1,000 lumen, 25,000 candela white light to the visible laser, IR laser and 60 mW VCSEL IR illuminator the IRIS 3 already has. Buy the IRIS 3 if you already run a separate weapon light or want the smaller, lighter unit: it weighs 6.4 oz against 8.5 oz and runs on a single CR123A. The lasers and the IR illuminator are rated the same on both.
What is the difference between the Holosun IRIS 3 and IRIS 4?
Going by Holosun's spec pages, four main things differ. The IRIS 4 adds a white light (1,000 lumens, 25,000 candela). It is larger and heavier (4.2 x 2.3 x 1.4 in and 8.5 oz against 3.2 x 1.97 x 1.34 in and 6.4 oz). It takes one 18650 or two CR123A cells, where the IRIS 3 takes one CR123A. And the controls differ: the IRIS 4 has independent fire buttons, a rear power selector and a three-button remote pressure pad, while the IRIS 3 has one center fire button and a dual-button pad. Both pads have a visible laser override.
Do the IRIS 3 and IRIS 4 have the same lasers and IR illuminator?
On paper, yes. Holosun rates the visible laser on both at under 5 mW, Class 3R (520 nm on the green GR models, 635 nm on the red RD models), the IR laser at under 0.7 mW, Class 1, 800 to 880 nm, and the IR illuminator at 60 mW VCSEL, with a top-mounted slider to adjust the IR beam. The IRIS 4 does not upgrade the laser or illuminator side; it adds the white light.
What battery does the Holosun IRIS 4 use?
Holosun lists the IRIS 4 battery as 1x 18650 or 2x CR123A. The retailer spec table shows CR123A only; we follow the manufacturer. The IRIS 3 runs on a single CR123A, which Holosun says is replaced through a front cap.
Green or red laser: is there a price difference?
Not at OpticsPlanet when we checked: each model sells in a green version (IRIS-GR3, IRIS-GR4) and a red version (IRIS-RD3, IRIS-RD4) at the same price as its sibling. Holosun lists the green laser at 520 nm and the red at 635 nm, both under 5 mW and Class 3R.
Building a night setup? See our best night vision goggles and best night vision monocular guides. Prefer a separate white light next to an IRIS 3? Compare options in our best rifle light guide. Looking at a higher-end laser aiming device built for military and police use? See our Wilcox RAID Xe review. Considering a green laser aiming device with an LED IR illuminator? See our Steiner DBAL-D2 review.