4" x 18" Kraft Crimped end mailing tubes. Economical Kraft Crimped end mailing tubes seal by pinching the ends. Tubes are fast and easy to close and stay closed - no need for tape. Ends open easily allowing them to be reused. Tubes are also recyclable. Sizes listed are the usable inside space of the tube. Actual tube lengths are longer. Tubes are 3-ply spiral wound. Sold in case quantities.