This is a 2-in-1 snoot for the Altman 650L Fresnel light. A different opening is derived by removing the mask.
Snoots, Barndoors, Grids, and Filters are essential accessories for any lighting system. These devices alter the shape, intensity, or color of the light output from your flash heads. Consider them as a painter would a brush, or a sculptor would a knife, or chisel.
Use of a snoot will result in a small circle of light, when it is attached to the front of your light source. The size of the circle of light will be determined by the opening of the snoot, its length, and the distance of the subject.