This a replacement O.S. Engines Piston Ring, and is intended for use with the O.S. 91HZ F3C, and 91HZ-PS Helicopter Engines.
|91FX||91RZ-H|| 91RZ-H DH
|| 91SZ-H PH
NOTE: This part may be compatible with other O.S. engines. Please check your owner's manual and cross reference the part number to verify that this is the correct part for your engine.