5x8 Self Seal Poly Bubble Mailers - Padded Envelopes (Inside Dimensions 4.5&times;7) (40 Bubble Mailers) (Inside Dimensions 4.57) Self-sealing, peel and stick, adhesive keeps contents secure and tamper proof. Extremely durable and lightweight polyethelene material helps save on postage. Strong seams, fins on two sides, and seamless bottom for maximum protection. Surface easily accepts ink, stamps, and labels Approved by shipping carriers.