The 'Clamshell' nickel plated, spring loaded, classic design tailpiece is often found on pre-war Gibson banjos. This tailpiece is also known as the 'Claw' tailpiece. This tailpiece can be fitted to 5-string and 4-string banjos.
Clamshell Banjo Tailpiece Vintage 5-String Banjo Replacement
Viking VS-370C Clamshell Banjo Tailpiece, Nickel plated copper at Hobgoblin Musi
Prucha 4-Hump Clamshell Banjo Tailpiece
Waverley Style Banjo Tailpiece by Leader Banjo Co
4 String Banjo Tailpiece Plate Replacement with Clamshell Design
Golden Gate P-111 Clamshell Style Banjo Tailpiece - Nickel