Recently, I sold my locking releases and bought a few of the 'one hand' releases. Well, I ended up with one too many. One has to go. The biggest, beefiest of the lot is 20" long from tip to tip. Built to last. $10 shipped. No paypal.
This is the kind that does not reqire two hands (one to hold the pluger, and one to lock it). Simply push to lock, much simpler than the 2 hand kind.