Dura Skrim R20WW Liner 6' x 15' Polyethelene Film - White 20 mil Food Grade - Aquaponics and Hydroponics Grow Beds Modular Tanks, Landfill Covers, Remediation Liners and Covers Shrimp and Fish Ponds; Earthen Liners; Underslap Vapor Retarders 11.5 has 3 foot seam, 17.5 Foot has (2) 3 foot seems For Custom Orders and lengths please contact by email