Gehmann 566-S Front Iris with 6-Color Filter Incorporates the proven Gehmann 510 iris Adjustable iris range from 0.5-3.0mm for precise control of sight picture and light Features six optically flat glass color filters: yellow, light green, orange, purple, dark grey, and light grey, each precisely positioned for optimal contrast Locking collar allows precise alignment of the V-mark Can be used as an iris only, with filters removed Removable steel threaded connector allows the addition of accessories such as a 0.0 diopter lens Anti-reflective black and matte silver exterior finish with matte black center to eliminate glare Includes instruction manual