ACL D15 Bearing offers the unique combination of design, metallurgy and engineering. These qualities come together to deliver what Honda drivers and engine builders expect from high performance Trimetal engine bearings. These -.50 Undersized ACL Race Series Connecting Rod Bearings are designed to withstand higher RPM conditions in big hp setups such as turbo, supercharged and nitrous applications!Features: *High strength overlay plate with reduced thickness offers improved fatigue properties. *Hardened steel backs on all rod bearings to improve the support of the bearing lining and assist with bearing retention in the housing. *Elimination of flash plating on the back of the bearings to improve heat transfer through the bearings and to maximize the grip between the bearings and its housing. *Increased eccentricity to compensate for bore distortion at high RPM and to assist in the formation of hydro-dynamic oil films. *Tight consistent wall tolerances to help you maintain consistent clearances.