F10 Fresnel Compatible The F10 Barn Doors are designed for the F10 Fresnel, and slide into its standard 13.1-inch (333mm) Drop-In Accessory Slot. Like with traditional Fresnel Fixtures, the leaves on the F10 Barn Doors are designed to be large enough to properly shape and control the output of an industry-standard 10-inch Fresnel. 8-Leaf Design Unlike traditional Fresnel Barn Doors, the F10 Barn Doors feature an 8-Leaf design, including four smaller "helper flags" that can rotate in and out adjust the shape of the output based on your needs.