ShieldNSeal 11&rdquo; x 23&rdquo; Black Vacuum Seal Bags With Zipper SNS 2500 Contains: 50 bags, 11" x 23" Shieldnseal BPA free all black vacuum seal bags with zipper reseal feature Super Thick (5mm), Durable, BPA-free plastic. Best, strongest, tightest vacuum heat seal. Keep food fresh 5x to 10x longer. Maintain nutritional value of foods and potency of herbs. Commercial grade flavorcomb channels allows sealers to vacuum out the maximum air for total freshness. One side Presealed with zipper. One side open. Requires Heat Sealer. Compatible with most sealers. Tested for optimal performance. Extra large size for bulk storage.