Good quality banjos have adjustable tailpieces (except for many of the "old time" banjos like the Deering Vega Old Time Wonder that has a ‘No-Knot’ small fixed tailpiece for traditional appearance and sound. The best adjustable tailpiece has no resonance of its own, it is better that it does not ring and interferes with the tone of the rim and tone ring. For example, all USA made Deering, Goodtime and Tenbrooks banjos have the excellent Deering adjustable tailpiece made of a non-resonant alloy.
The banjo tailpiece plays a very important role in the tone and volume of your banjo. Its prime function is to anchor your strings. Its secondary function is to angle your strings to exert maximum pressure on the bridge in order that the bridge transmits sound into the banjo head. Adjustable Waverley Style, Clam Shell, One hump and two hump, Scruggs type, Kershner and Nashville types are all available from Eagle Music.