This CP single piston and ring set is specified for the Acura B18C1 engine with an 82.0mm bore at a +1.0mm oversize. The listing indicates a single forged piston with ring set arranged for the stated bore and sizing. It is supplied to match the B18C1 dimensions and compression geometry referenced in the product title to facilitate correct replacement of that engine's piston assembly.
CP Piston & Ring Set for Acura B18C1 - Bore (82.0mm) - Size (+1.0mm) - CR (12.5) SINGLE PISTON