2 Pieces Binoculars Protective Rubber Objective Lens Cap 42mm For Telescope With Outer Diameter 52-54mm Drop Shipping - Microscope Parts & Accessories - AliExpress
Amazon.com : Opticron Rubber Objective Lens Covers 50mm OG L Pair fits models with Outer Diameter 60~62mm : Electronics
Amazon.com : Opticron Rubber Objective Lens Covers 50mm OG S Pair fits models with Outer Diameter 56~58mm : Spotting Scopes : Electronics