49mm Motorcycle Front and Rear Air Cylinder Block and Piston Kit with Head Gasket Kit for XV250 XV 250 Rebuild Kit This kit includes components designed to fit 49mm cylinder bores for front and rear cylinders on specific motorcycle models.It contains a cylinder block, piston, and head gasket suitable for engine rebuilds.The parts are intended for use in the restoration or repair of compatible motorcycles requiring replacement of worn or damaged internal engine components.This set supports the reassembly of the engine's upper end, proper compression and function when installed correctly.