Sold Out Quick view TwinPower TwinPower Advance Unit - 215533 Compare $37.95 $36.99 Twin Power 70-79 Big Twin 71-79 XL Advance Unit Replaces HD 32517-70TThis Part Fits:YearMakeModelSubmodel1971-1978Harley DavidsonFX Super GlideBase1974-1979Harley DavidsonFXE Super GlideBase1979Harley DavidsonFXEF Fat BobBase1977-1979Harley DavidsonFXS... Currently Out of stock. On order! Currently Out of stock. On order!