Check the listing for details. E. Gerber 50 Mylites2 & 100 Half Backs Standard Size E725M2 700HB Double Board. Condition: New. Listed at 49.99 USD. This Auction contains: 1 Sealed Pack containing 50 E. Gerber Standard Comic Book Mylites2 Mylar Protective Sleeves (50 total) 1 Sealed Pack containing 100 E. Gerber Standard Half Back 100% Acid Free Backing Boards 24 Mil (100 total) Protect Your Collectibles from the Effects of Aging: The Mylites are made of Mylar and used by National Archives and the Library of Congress so they will be good for your comics! Humidity Volatile Poly Bag Breakdown Acid Migration Oxygen Decomposition Insects Ultra-Violet Fading Molds & Mildew Oils & Greases The Backing Boards are:Made from 100% Acid-Free, 24 Mil Thick cardboardEnsuring extra rigidity and protectionProduced with a 3% alkaline buffer Maintains ph of 8.0+ Meets U.S. Government Standards for Archival Storage Dimensions: Mylites+ are 7 ¼ " x 10 ½ " plus 1 ½” flap on the bagsHalf Backs are 7" x 10 ½ ", 24 Mil Thickness Shipping is free to the Continental United States. Check out our other E Gerber supplies listing as well as out comic and card listings.