Use these patches to add stainless steel d-rings to a STAR inflatable kayak, PVC raft or urethane inflatable. For glue, use Clifton Urethane Adhesive or Stabond. For tips on patching PVC, click .Comes in 3 sizes:1" D-Ring, 4" PVC Patch1.3" D-Ring, 4.5" PVC Patch1.5" D-Ring, 6" PVC Patch