|00:43The "Clamshell Tailpiece" is so named because, well, it resembles a clam shell. The simple design can accept either ball-end or loop-end strings, anchored underneath the humped flap which flips up (like a clam shell) to allow for string changes. The Clamshell Tailpiece has one simple adjustment: to change downward pressure applied to the bridge.
The often-copied design originated from a Grover style "Four-hump" clamshell banjo tailpiece. The original Grovers are rare and beautiful tailpieces that were seen on some of Gibson's most desirable banjos including the pre-war Granada.