This eyepiece protective cover is for use on the TE-10Z 20-60X eyepiece. It does not fit the TE-20H 25X Long Eye Relief eyepiece. Both are eyepieces for the Kowa 880 series spotting scopes. Installation is easy. Twist and pull off the multiposition rubber eyecup that comes with the zoom eyepiece. (I don't miss having the adjustable rubber eyecup because there is a roof over the shooting line and glare from direct sunlight is not a problem.) This exposes the metal threads. Next simply screw the protective eyepiece in place. The glass in the end of the protective cover protects the more expensive eyepiece lens from trash and scratches. The eye relief with the cover in place is such that it is only at the highest powers (approaching 60X) for the zoom lens that my prescription shooting glasses sometimes "hit" the glass surface of the protective cover. For lower powers, there is sufficient eye relief with the cover in place that my glasses do not come near. I'm glad to have this protection for my eyepiece.
Pros: Excellent fit
This review was written in the old system and had content requirements that are different than reviews written today.