CD/DVD Disc Mailer - 25-pack Least Expensive First Class Postage for One Disc - GUARANTEED! US Postal Service approved for $.45 first class postage. No other sleeves are necessary. Using sleeves may push the total weight over an ounce and require higher postage. Each package of mailers comes with a letter from the Post Office stating that the mailer is not subject to the $.20 per unit surcharge! The mailer holds the discs very thightly in place so as not to damage the media. Self-Seal - Simply peel the adhesive backing and fold closed. The mailers are made of very thin and lightweight .008 board. The material is thicker than paper but still thick enough to protect your disc. 50-pack, 100-pack, 300-packs and 500-packs available - See our Amazon store for details.