NE Brand / D&K Honda 30.8mm O-ring. This size of O-ring is used on probably a million different models of Honda motorcycles. For most of the 70's bikes it's used as the tappet cover O-ring. It also has many other uses on other models of Honda bikes.
Inner Diameter: 30.8mm
Outer Diameter: 37mm
Thickness: 3.2mm
Equivalent to Honda OEM part number: 91302-001-020
Fits Honda:
Z50A - 1969-1978
Z50R - 1979-1981
S65 - 1965
C70 Passport - 1971-1982
CL70 Scrambler - 1969-1972
CT70 Trail - 1970-1982
SL70 Motosport - 1971-1973
XL70 - 1974-1976
CT110 Trail - 1980-1982
XL175 - 1973-1978
CB350F - 1972-1974
CB350K - 1968-1973
CB350G - 1973
CL350 Scrambler - 1968-1972
SL350 Motosport - 1970-1972
CB360K - 1974
CB360T - 1975-1976
CB360G - 1974
CJ360T - 1976-1977
CL360 Scramber - 1974-1975
CB400F Super Sport - 1975-1977
CB500K - 1971-1973
CX500 - 1978-1982
GL500 SIlver Wing - 1981-1982
GL500I Silver Wing Interstate - 1981-1982
CB550F Super Sport - 1975-1977
CB550K - 1974-1978
CB750A Hondamatic - 1976-1978
CB750C Custom - 1980-1982
CB750F Super Sport - 1975-1982
CB750K - 1969-1982
CB750L - 1979
CB750SC Nighthawk - 1982
CB900F Super Sport - 1981-1982
CB900C Custom - 1980-1982
GL1000 Gold Wing - 1975-1979
GL1100 Gold Wing - 1980-1982
GL1100I Gold Wing Interstate - 1980-1982
and many others . .