Yens Poly Mailers 12 x 15.5 M5 Envelopes Shipping Bags Self-Seal, Tear-Proof, Water-Resistant & Postage-Saving Lightweight Plastic 500M5, 500 Piece High quality self sealing mailers Water, tear and puncture resistant The dark grey inner layer provides confidentiality Pressure sensitive adhesive provides a high strength durable closure, water and dirt resistant Size: 12 x 15.5 500 piece