PackagingSupplies 2.5 Mil Poly Mailers, 12  x 15.5-Inches, 500 / Case 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.