EcoSwift Size #5s 12 x 15.5 Poly Mailers Self Sealing Bulk Shipping Supplies Packaging Materials Envelopes Bags EcoSwift Size #5s 12 x 15.5 Poly Mailers Self Sealing Bulk Shipping Supplies Packaging Materials Envelopes Bags Size: #5s Dimensions: 12" x 15.5" Usable Space: 12" x 14.5" EcoSwift Self-Sealing, Peel and Stick Adhesive