New includes 2 pistons, one set of piston rings, 2 wrist pins (piston pins). You will need to supply the second set of piston rings.
According to chatgpt:
Harley-Davidson part #21900050, it is the Screamin’ Eagle 4.000-inch Bolt-On Piston Kit, standard version. It’s associated with 4.000-inch cylinders and requires ECM recalibration after installation.