Burris FastFire Red-Dot Reflex Sight - No Mount (4 MOA Dot Reticle) The fast Fire II provides the only fully waterproof unit in its product category The fast Fire II is very small and mounts very low The housing is made of metal for strenght and durability 20,000 hour battery life Waterproof Steel construction Increases your shooting speed and accuracy 20,000 hour battery life Waterproof Steel construction Increases your shooting speed and accuracy