Viridian 9810159 Venta Black 1 x 20 mm 3 MOA Green Dot
https://www.tandktactical.com/shop/647581796405-viridian-9810159-venta-black-1-x-20-mm-3-moa-green-dot-43993
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Venta Green Dot Sight. 3 MOA Green Dot. IPX6 waterproof.