4pcs Engine Pistons Rings Set made from forged aluminum with a hard anodized finish.Designed for performance applications, these pistons are engineered to enhance engine efficiency and support long service life.The set features a cylinder bore of Φ82.00mm and a compression ratio of 11:1, optimized for balanced power and fuel efficiency.Piston pin diameter is Φ22mm, with ring thicknesses of 1.2mm for the first ring, 1.5mm for the second ring, and 2.0mm for the third ring. This piston set is designed to fit models including F20, F23, F33, F55, F56, and G30, and is compatible with engine applications associated with part numbers 11258678931, 11258657760, 11259468869, 11259468871, 11258618503, and 11258638450.The design allows for precise fitment and under demanding conditions. This is not an OEM product.Brand/model references are included solely to assist with compatibility identification.