The saddle diameter can be adjusted, and can be fixed to any number of items such as CD pipes, PF pipes, VE pipes, steel pipes, cables, etc. Grooved opening for easy diameter adjustment. You can fix it firmly with one screw. D8/13/18 has anti-shift and screw catching. Compatible Diameter: 10.2 - 1.2 inches (26 - 31 cm), Compatible Tube (Nominal 2 mm)