The Askar 0.7x universal full-frame reducer is a 3" triplet design with one ED glass, compatible with the 107PHQ, 130PHQ, and 151PHQ. This reducer effectively shortens exposure time and dramatically increases field of view. When used with 107PHQ it achieves f/4.9 at 524mm; with 130PHQ it achieves f/5.4 at 700mm; with 151PHQ it achieves f/4.9 at 740mm. Standard 55mm back focus with M68/M54/M48 adapters included.