These are thin, flexible (cut with scissors) translucent sheets that soften LED emitter glare and do it without chopping the snot out of overall light transmission (Lens that forces a bright light go dim).
One part number scatters light wide, while another part number focuses light into a narrower beam (like what is needed over a dining table).
This may be worthwhile chasing down a distributor via the website. I definitely would NOT recommend using these diffusers with an incandescent light bulb.
http://www.luminitco.com/