The APO-Televid Aspherical eyepiece boasts optical superiority and durability with its wide angle 60 degree field of view, fully multi-coated lens system, rapid interchange bayonet attachment method, rubberized function elements and twist out eye cup. The nitrogen filled eye piece is submergible to 17 ft. and is completely fog/shockproof. Designed to fit the APO-Televid Spotting Scope Body (sold separately.)