Kahles Tenebraex Killflash ARD 50mm

Killflash scope diameter 56mm
 
Fits on following models K312i, K318i, Helia 2 2-10x50i, Helia 3 3-10x50i
The killflash/ARD (anti-reflective device) or honeycomb filter is a darker colored honeycomb patterned filter that threads on over the objective lens of your scope.
This is meant to cut down on glare and obscure or camouflage the obvious flash or shininess of the lens when looking at it from the front. You can be perfectly concealed and on target, and if your quarry catches a glimpse of that lens flash, your cover’s blown! Mostly used by marksmen and snipers in the military.