An aspect of an oboe or a bassoon, nut not of a clarinet
John Carlson trumpet, pocket trumpet & 
flughorn... [DOC] [TLE] Patent US5417135 - Pad assembly, pad cup, and retainer for wind ... [PAR] May 23, 1995 ... As a result, the skin is no longer held to the tone hole and air leaks develop at .... 
Alternatively, the pad nut, having a flanged region opposite its curved tip, ... 
woodwind instruments such as the clarinet, oboe, bassoon, or saxophone.