The 031-221 is a Bulkhead BNC Jack, made of nickel-plated brass body and PTFE insulator. This bayonet style connector allowing for quick connect and disconnect with a positive locking mechanism. Mating is achieved with just a quarter turn of the coupling nut. With a classic, dependable design, BNCs are suited to accommodate a large variety of RG and industry standard cables, in a variety of termination styles.