Which circular multi-contact connector requires a 90-degree clockwise twist to couple?

• A. Breech coupling
• B. Bayonet coupling
• C. Quick-disconnect coupling
• D. Threaded coupling

Answer: (A)

Locking by a quarter-turn breech mechanism is being tested here. In breech coupling, once the connectors are aligned so the keying features engage, you rotate a locking ring or collar through about a 90-degree turn in the clockwise direction. That single twist pulls the two halves together, engages the locking lugs, and seals the connection, giving a secure electrical path with a defined orientation. This quick, positive engagement is what makes breech coupling distinct, as opposed to threaded couplings that require multiple turns to thread on, or quick-disconnects that use push-pull release. While bayonet-type connections also involve a twist, the breech style specifically uses that 90-degree clockwise quarter-turn to lock the assembly in place.