The black 3" Inky Barndoors from Altman have a lightweight 2-leaf, snap-on design that directs the fixture's light output while controlling spill light. The barndoor leaves can be moved independently for the 100 Fresnel.
Designed specifically for the 100 Fresnel
Features a 2-leaf adjustment design
Light's beam spread can be controlled by swinging the barndoor leaves into the fixture's beam