This is a 1973 Kawasaki F11M F11 250 NOS OEM STD Piston with part number 13001-058. It is an out of box special, meaning that it has never been used but may not be in its original packaging. This piston is compatible with Kawasaki motorcycles and is an original OE part. The brand of this piston is Kawasaki. It is a great addition to any Kawasaki motorcycle owner's collection or can be used to replace a worn out piston. piston box1