Originally produced for a U.S. military order, this M231 leaves the line only after each unit passes full water-immersion, pressure, and thermal-shift checks, the tightest inspection tier specified in the contract. It keeps the familiar side buttons, 1 MOA dot with 65 MOA ring, and quick-detach rail clamp of the EXPS3-0, then adds a front tie-down hole because the military is obsessed with tying stuff down.

Because these are contract overruns, availability to commercial buyers is limited and rare. 

Specifications

• Reticle: 65 MOA ring with 1 MOA center dot

• Dimensions (L × W × H): 3.8 × 2.3 × 2.9 in (96.5 × 58.4 × 73.7 mm)

• Weight: 11.2 oz (317 g) with battery

• Tie-down feature: 0.20 in stainless through-hole

• Adjustments: 0.5 MOA per click, windage and elevation

• Brightness: 20 daylight + 10 night-vision levels

• Power source: 1 × CR123 (included)

• Battery life: ~1,000 h at setting 12, 25 °C

• Waterproof rating: 66 ft (20 m)

• Thermal drift: < 2 MOA from −40 °C to 60 °C