This is an official Pentax fixed diopter to attach to the viewfinder eyepiece, to adapt the viewfinder image to the user’s eye-sight when the built-in diopter adjustment is insufficient (or there isn’t any). This adapter was originally available from -5 to +3 diopters, and this particular item is -3 (minus three).
- Fits of all M-series Pentax SLRs and newer, including later DSLR models.
- May fit Ricoh SLR’s too, but please check. If in doubt please send us the camera model you’re hoping to use it with.