THIS RING SET IS FOR ONE PISTON DESIGNED TO FIT ONAN ENGINES WITH 3 9/16 BORE THAT USE PART NUMBER 113-0296 .030 RING SET .THAT IS MOST OF YOUR P224 NH NHC PLEASE CHECK YOUR PART NUMBER BEFORE ORDERING . THESE ARE DESIGNED FOR EXTRA OIL CONTROL IN USED CYLINDER.AND WILL FIT YOUR OEM PISTONS .THESE ARE ALSO AVAILABLE IN 10-20 THESE FIT THE JOHN DEERE T260