The Landini 976974M1 is a genuine OEM piston ring set designed for engines with a 91.44mm (3.6 inch) bore. This set typically includes rings with thicknesses of 2.38mm, 2.38mm, and 4.76mm, ensuring optimal engine performance and compression. It is compatible with Perkins AD3.152, A3.152, and AT3.152 engines, commonly found in a wide range of Landini and Massey Ferguson agricultural tractors. This part is a direct replacement for original equipment, ensuring proper fit and function.