Technical Specs Item Helical Insert Type Free Running Material 304 Stainless Steel Thread Type Metric Coarse Thread Direction Right Hand Dimension description: for example: M3x0.5x2D M3 means the thread diameter is 3mm, 0.5 means the thread pitch is 0.5mm, 2D indicates that the maximum length of the Helical Insert after installation is 2 times of the diameter, Length 1D,1.5D,2D,2.5D,3D （Maximum stretch length after installation ）