Vertex Top End Gasket Kit Yamaha YZ-WR125 05-21/Fantic XE-XX125 21-22 Product Info: Vertex’s top end gasket kits are designed for tackling the job of replacing a piston. Each set includes the head, base, exhaust pipe, and power valve gaskets necessary for a top-end rebuild. Formed rubber valve cover gaskets are not included. Multi cylinder applications include all necessary components to rebuild all cylinders.