Genuine Honda petcock strainer bowl o-ring for the many of the Honda twins. This o-ring goes between the strainer bowl and the petcock body. If you've got an original petcock that can be rebuilt, make sure to clean every passage way thoroughly to let the gas flow freely. It's great to re-use the stock part when it's serviceable.
Honda Part Number: 16075-GHB-B00 (2.4x18.6mm)
Fits on Honda Part: 16950-292-000 (petcock) and other petcocks
Fits Honda: CL175K Scrambler - 1970-1973
CL200 Scrambler - 1974
MR250 - 1976
CB350K - 1968-1973
CL350K Scrambler - 1968-1973
CB350G - 1973
SL350 - 1969-1973
CB360K - 1974
CB360G - 1974
CB360T - 1975-1976
CL360K Scrambler - 1974-1975
CB450K - 1965-1974
CL450K Scrambler - 1968-1974
CM450A/C/E - 1982-1983
CB450SC Nighthawk - 1982-1986
CB650SC Nighthawk - 1983-1985
CBX - 1982

also fits many of the 80-250cc dirt bikes and others. . .