Astromania 0.965" to 1.25" Adapter - Allow You use 1.25" Accessories on 0.965" Telescope! Eyepiece Adaptation: 1.25" (31.7mm) inside. Optical Length (not counting the 24.5mm barrel): about 30mm. Telescope Adaptation- 24.5mm (0.965") male barrel Allows you to use 1.25" eyepieces in any 0.965" telescope focuser, star diagonal or holder. All metal construction and anodizing aluminium process, durable for long time use.