T10P Poly Sure Opaque Poly Mailers measure 350mm x 400mm. Being made from high standard, co-extruded 45 micron polythene, they’re strong, waterproof, puncture resistant and tear resistant. This is a market leading environmentally-friendly product that is fully recyclable, 100% degradable and printed with only water-based inks. The tamper proof high tack adhesive seal and heat sealed edges ensure items are safe and confidential and because these are extremely lightweight they can substantially reduce mailing costs.