Size: Pull Pin Spring Knob for Stationary Bikes M16 M18Knob for most bikes.

Material: Made from steel iron and ABS, it is sturdy and durable.

Feature: The knob comes with a built-in spring handle, will not scratch your hands due to winding

Convenience: The product is easy to install, convenient to store, and easy to carry.

Application: Suitable for exercise bikes, strength equipment, fitness equipment, some weight benches, etc.