Piston including piston pin and piston rings compatible BRIGGS STRATTON lawn mower engine lawn mower models 09 - 13 3.5 - 5 hp TECHNICAL DATA Piston size: + 0.020" Ø of the bolt in mm: 12.30 Ø of the cylinder in mm: 65.60 CODE: ORIGINAL CODE: BRIGGS STRATTON 298906 393821 CZ