20ft seal for mounting a truck cap or camper shell that weighs 200 lbs or less. Fills all bed rail gaps. For 8 ft beds purchase ASIN: B00C7VU9BA | Complete kit includes seal, butyl tape, alcohol pads and detailed instructions | High quality, long-lasting automotive grade EPDM rubber. Preferred by professional installers over PVC/foam seals. | Excellent compression set resistance for maximum service life and vibration absorption | No need to replace this seal every time your cap is removed.