This is a Killflash I made for the ACOG optic. There are several options available for individual needs. This Killflash is attached the same as Trijicons, but made with superior quality as seen in the gallery reel. 
 
Some features include a lanyard ring, being stronger at a cost of weight, a smaller and shorter profile allowing for more real estate on your preferred firearm, and being a more affordable option to Trijicons.
 
Options include-
 
Color being Matte Black or OD Green,
Cap being solid or with a center opening,
Cap opening to the left or right of the firearm.
 
It is recommended that right handed shooters purchase the left open option, and left handed shooters purchase the right open option , as this will dictate which offhand you would normally use to open the killflash while in use.