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. 5.6″ x 2″ x 2.5 (143 x 51 x 64 mm). 11.5 oz (325 g). Submersible to 10 ft. 1 Weaver or MIL-STD-1913 rail. Two 1.5 V AA batteries. Supports lithium, alkaline, or rechargeable. Lithium: 1,000 continuous hours at nominal setting 12 at room temp. Alkaline: 600 continuous hours at nominal setting 12 at room temp. Then select “Return this item” from the drop-down menu. You will then need to select a reason for your return. We value our customers and strive for excellent customer service.