OSE-S-OFB Reasonable Optical Flats These lower cost optical flats have minimal reduction in surface quality and are suitable for most applications.
OSE-S-OFBP Reasonable Optical Flats, Polished These lower cost optical flats have minimal reduction in surface quality and are suitable for most applications.
OSE-S-OPB Reasonable Optical Flats, Polished These lower cost optical flats have minimal reduction in surface quality and are suitable for most applications.