Series 345 is a double shut-off series with both a valved coupling and nipple. The specially designed valve provides an extremely high rate of airflow. This series is well-suited for breathing air diving applications and for applications that demand a closed system when disconnected, such as surface air diving. Like most other CEJN breathing air couplings, Series 345 offers one-hand-operated connection, an integrated safety feature that guards against unintentional disconnection, a grip-friendly locking sleeve, and a broad connection range.