The SEP-20-60 zoom eyepiece is exclusively designed for the PROSTAFF 5 Fieldscope series and is ideal for detailed observation. Offering fully multilayer-coated lenses, long eye relief for viewing comfort with eyeglasses and a bayonet mount with lock for easy attachment and release. Water resistant when attached to Fieldscope body.  Compatible with all straight and angled body PROSTAFF 5 Fieldscopes, this eyepiece provides 20-60-power magnification with 82mm bodies and 16-48-power with the 60mm bodies.