These are removable prescription eyeglass lens holders for the current DK2 (MUST BE USED WITH THE DK2'S "B" LENSES). These were made to fit my own lenses from an old pair of glasses, so the "B" STLs will likely need to be modified to fit your own lenses. These have increased my FOV tremendously as I can get much closer to the lenses. The bridge of my nose is also much happier, and my DK2 is finally comfortable. Note: You must use the DK2's spare set of "B" lenses with this adapter, the "A" lenses will be too tall with the adapter installed and the image will be out of focus. Print at 0.10mm layer height (high res) with rafts but no support. Try your own experimentation with infill and shells, my last print was 15% infill with 4 shells, and I was happy with the result.