This is the small petcock seal(O-Ring). It seals between the petcock base and the tank. You should replace this seal when you remove the petcock. Replacement for Yamaha part #434-24532-00-00. Not OEM part, but good substitute. Made from Viton fuel proof material.

This is for the seal(O-ring) only, ref #21 in picture. Other parts are not included and is for reference only.

Some applications include:

YL1 66-67
YL2 67-68
YAS 68
YLCM 68
AS2 69
L5T 69-70
HS1 70-71
HT1 70-71
CS3 71
CS5 72
LS2 72
TY175 75-76
TY250 74-77
RS100 75-76
RS100 75-76
DT125 78-79
DT175 78-79
MX175 79

PLEASE READ AND UNDERSTAND DETAILS AND PAYMENT/SHIPPING TERMS BEFORE BUYING. THANKS.