Check the listing for details. Durhams Tackle Flip Open Scope Cover Model# 46mm. Condition: New. Listed at 4.99 USD. Durhams Tackle Flip Open Scope Cover Model# 46mm Features a watertight friction mount and semi-O-ring that securely anchors the cover, sealing out dust and moisture. The lens covers feature two finger tabs extending from both sides of the cap, perfect for right- or left-handed shooters. Silent spring hinges will not spook game. Weigh less than an ounce. Rugged polymer material can withstand the hottest or coldest climates. To select the correct cover, measure the outside diameter with calipers. Select the closest measurement from the table below. Durhams Tackle Butler Creek Comparison Chart: Model# Size Inches (mm) Model# 30mm 02A 1.181 30 MO30025 34mm 3 1.34 34 30035 36mm 7 1.429 36.3 30070 38mm 10 1.5 38.1 30100 41mm 17 1.612 40.9 30170 42mm 19 1.646 41.8 30190 43mm 20 1.7 43.2 30200 44mm 21 1.735 44.1 30210 45mm 23 1.76 44.7 30230 46mm 26 1.82 46.2 30260 47mm 27 1.84 46.7 30270