The cavity dowel is intended for fine assembly of light components. It is ideal for hollow materials. When turning, it creates the so-called a plug that prevents the dowel from being pulled out. During disassembly, the dowel returns to its original shape. The dowel is made of nylon. Advantages: Especially suitable for single and double gypsum boards; The necklace prevents the plug from slipping into the hole; The edges on the collar prevent the cap from turning.