Raft valve doughnut patch for replacing valves. Patch diameter = 8 3/8", inner hole = 1 1/4". Patch is NRS Pennel Orca material. Use Clifton Hypalon Adhesive and Clifton Hypalon Accelerator for gluing to Pennel Orca and other hypalon boat materials. Patch can also be glued to PVC- and urethane-coated boat materials, using Stabond Adhesive. You may need to enlarge the hole for some valves. See the "How to Replace a Raft Valve" video for complete instructions.