Model 512 is EOTech's most popular holographic weapon sight. It?s ideal when you need the best in speed and versatility, without night vision compatibility.p - Length/Width/Height: 5.6" x 2" x 2.5" (143 x 51 x 64 mm).br - Weight: 11.1 oz (312 g).br - Water Resistant: Submersible to 10 ft. (3 m) depth.br - Mount: 1" Weaver or MIL-STD-1913 rail.br - Power Source: Two 1.5 V AA batteries. Supports lithium, alkaline, or rechargeable.br - Battery Life: Lithium: 1,000 continuous hours at nominal setting 12 at room temp. Alkaline: 600 continuous hours at nominal setting 12 at room temp.