Description ***View our Size Chart to see if your Optic is compatible*** The On Glass OG Mini Kit is a compact digiscoping system designed specifically for binocular users who want a simpler, lower-profile setup. Its one-piece Mini Ring/Spacer Combo fits compatible eyepieces from 1.55" to 1.8", eliminating the need for a separate spacer, while the MagTab and Alignment Tool provide fast, repeatable phone-to-optic alignment. Universal phone compatibility means no proprietary case is required, making it an easy option for capturing photos and videos through your binoculars in the field. Sizing Fits all optics with an eyepiece outer diameter of 1.55 - 1.8". View our Size Chart to see if your Optic is compatible. How to measure: To measure your spotting scope or optic eyepiece, place a tape measure across the widest point of the outer eyepiece housing. Measure straight across the center from one outside edge to the other to determine the eyepiece diameter. Specs Fits Binoculars with 1.55" - 1.8"eyepiece diameter Includes (1) OG Mini Ring/Spacer Combo - A one-piece adapter matched to your binocular&';s eyepiece diameter(1) MagTab - Low-profile magnetic plate that attaches to your phone case (or MagSafe Backer) with 3M tape(1) Alignment Tool - Centers your phone&';s camera perfectly to your optic during setup Manufacturer Warranty Lifetime against manufacturer defects