12" x 15.5" Poly Mailers Envelopes Bag, Waterproof and Tear-proof Postal Bags, White, 500 Pack Lip Size: 1.5 +/- . 2.5-millimeter thickness (+/- 5%). Usable Dimensions: 12 x 15.5. Paper Liner: Clear with antistat. Adhesive: Synthetic rubber  Hotmelt,  minimum +/- 1/8.