This product is a pair of M4 (4mm) CB radio mounting bracket knobs in black. Designed to be universal, these knobs are specifically tailored to fit a CB radio. The unit type is a set of two knobs, making it easy to securely attach your CB radio to a mounting bracket for stable and convenient placement in your vehicle or workspace. With a durable and compact design, these CB radio mounting bracket knobs provide a reliable and versatile solution for securely holding your CB radio in place.