The Hawke Endurance Reflex Sight 1x21 (Model 12151) is an ultra-compact optic engineered for rapid target acquisition across handguns, shotguns, and long guns. Featuring a 21 mm objective lens with 1x magnification and unlimited eye relief, this reflex sight provides parallax-free operation from 9 metres to infinity. It incorporates a user-selectable green multi-reticle system powered by a single CR2032 battery, offering up to 50,000 hours of runtime aided by Auto Illumination Mode (A.I.M.) that enters standby after 5 minutes of inactivity. Designed with a native Shield RMSc mounting footprint and supplied with a removable low-profile Weaver/Picatinny base, the sight weighs just 26 g bare (48 g with rail mount) and delivers shockproof, all-calibre recoil resistance.

Key Features

• Multi-Reticle Green Illumination: Switch between a precise 3 MOA center dot, a fast-acquisition 30 MOA circle, or a combined circle-dot pattern to suit varied shooting disciplines.
• 10-Stage Digital Brightness: Equipped with 8 daytime brightness settings and 2 night-vision compatible stages for precise contrast in changing light environments.
• Motion-Activated Power: Auto Illumination Mode (A.I.M.) powers down the unit after 5 minutes of zero movement and awakens instantly upon movement detection.
• Dual Mounting Interfaces: Direct-mounts to slimline pistol slides using the native Shield RMSc footprint or installs on rifles and shotguns via the included low-profile Weaver clamp.
• Precise Windage and Elevation: Turret adjustments feature a reliable 1 MOA click value for zeroing accuracy.
• All-Calibre Shockproof Construction: Built to withstand the harsh reciprocating slide forces of centrefire handguns and the heavy recoil of magnum shotguns and rifles.

Technical Specifications

• Magnification: 1x
• Objective Lens Diameter: 21 mm
• Reticle: 3 MOA Dot, 30 MOA Circle, or Circle-Dot Combo (Green illumination)
• Brightness Settings: 10 stages (8 day, 2 night vision)
• Eye Relief: Unlimited
• Parallax: Parallax-free from 9 m (10 yd) to infinity
• Click Value: 1 MOA
• Power Source: 1 × CR2032 3V lithium coin cell
• Battery Runtime: Up to 50,000 hours (medium brightness)
• Dimensions (Sight Only): 41 mm L × 24 mm W × 26 mm H
• Dimensions (With Base): 41 mm L × 31 mm W × 36 mm H
• Weight: 26 g (sight only) / 48 g (with Weaver base)
• Footprint: Shield RMSc (native) / Weaver rail (via included mount)

Who is the Hawke Endurance Reflex Sight 1x21 for?

• Slimline pistol shooters using RMSc slide cuts — Direct-mounts to factory optics-ready slides using the native Shield RMSc pattern, adding only 26 g of weight and a compact 24 mm width to preserve handgun balance.
• Dynamic carbine and shotgun shooters requiring multi-reticle switching — Allows rapid toggling between a fine 3 MOA dot for precision and a 30 MOA circle for close-quarters speed across a runtime of up to 50,000 hours on a single CR2032 battery.

Less suitable for: Target engagements beyond 100 to 150 metres, which require a magnified riflescope or a reflex sight paired with a dedicated optical magnifier; and firearms cut exclusively for larger footprints (such as Trijicon RMR or Leupold DPP) without an adapter plate, which require a full-sized reflex sight.