3" x 4" - 1 Mil Poly Bags on a Roll. These bags are on an industry standard core which makes them compatible with all automatic packing equipment. Roll converts from 1" to 3" core. Bags are pre-opened at one end and sealed at the other. Perforated for easy tear-off. Manufactured from 100% virgin film. FDA and USDA approved. Close bags with twist ties, bag tape or heat seal.