8 pcs Forged Pistons with pins and rings for S65 IQ-beam Rifle Drilled Forged Connecting Rods Contains: - Piston x 8 - Piston pin x 8 - Pin lock x 16 - Piston ring x 8 Tolerances: - 0.001 mm for pin hole - 0.005 mm for diameter - 0.04-0.06 mm clearance between cylinder and skirt Features: 1.Phosphate coated for improved oil adhesion and lubrication. 2.Moly coated skirt to reduce friction between piston and cylinder wall. 3.Oil holes in pin hole for better lubrication of piston pins, enhancing durability under temperature and rpm. 4.Lightweight design with optimized mass center for smooth V8 engine. Rings made in Taiwan. Fitment: - Engine: S65 - Models: - 2008-2013 E90 E92 E93 M3 - 2009-2014 Wiesmann MF4-SM159 Specifications: - Part Number: 061MP - Piston Material: 4032 - Rod Material: 4340 - Bore Size: 92mm - Compression Ratio: 12:1 - Compression Height: 27.5mm - Pin Size: 21mm - Overall Height: 51.52mm - Ring Size: 92x1.2+1.2+2.5mm - Rod Length: 140. 7mm for S65B40 Compatibility Disclaimer: This is an aftermarket replacement part. Any brand names or model designations mentioned are used solely for the purpose of demonstrating compatibility.