Soft PVC pad to glue on a PVC or Hypalon inflatable boat, to accommodate the Berkley Mount Base with Lock, which is the basis for most Berkley boating accessories. It features grooves to follow the shape of the boat easily and find extra grip. Supplied with four 1/4 x7/8 (22mm) 304-grade stainless steel bolts. Base dimensions: 158x113mm. This unique pad can also hold start ports, from some other brands (using metrical bolts). Important notice: before screwing a star port on, always carefully measure how deep you can go, to ensure your M6 bolts are not too long, to avoid damaging the boat. Dimensions of the chamber: diameter 32mm, depth: 12mm.