Bought these at a auction. The only identifying information was a note that said 808nm Flats. Looks like glass with a coating or thru doping. I do not know and these are sold as is. The box they came in said DILAS, The Diode Laser Company. these were from a lab that went out of business. They seem to have a different shade, but i have no way to grade or test. I have these in 3 sizes. With adhesive from something they glued on them, some without. This group HAS adhesive, see pictures. There are lots of clear areas without adhesive.  Shipping in a medium flat rate box Priority mail. no cost for extra items. I have others without adhesive in other auctions.