Keep your glass free from dust and scratches with Monstrum Bikini Scope Lens Covers! The flexible bikini covers secure snugly across the length of your rifle scope, protecting you glass from the harsh elements when not in use. Available in multiple lengths and diameters for fitment across a variety of rifle scopes - from 26 mm up to 65 mm scope objective diameters. Purchase the size that corresponds to the outside diameter of your rifle scope objective bell - the end opposite of the eyepiece. Note that this measurement is different than the diameter of your objective lens. Available in: 26-30 mm diameter 31-42 mm diameter 43-52 mm diameter 53-58 mm diameter 59-65 mm diameter All Monstrum products are backed by a lifetime guarantee.