PVC dowels are serrated on the inside for better screw grip. Flexible construction allows dowel expansion and firm grip even in the case of dowel applications on hollow materials. The side feathers stabilize the dowel in the wall and prevent its rotation around the screw axis. Solid plug, for use with plywood screws, wood screws and spacer screws. The rim prevents the plug from slipping into the drilling hole, but also allows installation through pressure. Advantages: Anti-rotation wings prevent the plug from turning in the drilling hole; Expansion-free plug helps prevent damage to tiles and plaster; Plug geometry offers high load-bearing capacity in solid and semi-rigid building materials.