This is a standard (STD) engine piston kit used primarily on Cummins ISL/QSL 8.9–9.0 L engines, featuring a two-piece piston. The kit is installed inside the cylinder block, connected to the connecting rod via the piston pin. Its function is to absorb the pressure generated by combustion, transfer the force to the connecting rod and then to the crankshaft, seal the combustion chamber via the piston rings, control oil consumption, and transfer part of the heat from the piston to the cylinder liner and the cooling/lubrication system.
It is always a good idea to check the ESN (Engine Serial Number), CPL, the Cummins QuickServe/OEM catalog, engine model, horsepower/rating, piston type (1-piece vs. 2-piece), the number stamped on the cylinder head, and the dimensional comparison.