This piston rings set includes 6 individual rings designed for use with M272 2.5L and 3.0L V6 DOHC engines.Compatible part numbers: 2720303717, 2720304017, A2720301018.Cylinder bore diameter: 88 mm.Bolt diameter: 22 mm.Bolt length: 48 mm.Ring thicknesses: 1.5 mm, 1.8 mm, and 2.5 mm.Fits select models including E-Class (W211, W212), C-Class (W203, W204), CL-Class (C209), (W221), CLK-Class (C209), CLS-Class (C219), GLK-Class (X204), ML-Class (W164), R-Class (V251), SL-Class (R230), SLK-Class (R171), and CL-Class Coupe (C216).Compatible with M272 E25 (2496 cc) and M272 E30 (2996 cc / 2997 cc) engine variants.Standard specification – no cylinder bore expansion required.