Fuel injector o-ring, the bottom of the injector. Sold as a full set of four (4) for a complete engine.
These fit all 16v 4AGE and 4AGZE engines. They also fit all 5SFE, 3SGE, and Gen3+ 3SGTE engines but they do NOT work on the Gen2 3S.
OEM Toyota Part Number: 23291-41010