Get the KLX/DRZ 110 seat, they fit the Atomik Pro Xs! Not the CRF50 seats, the only seats they fit is the Avenger, Moto-x and they shitty 50cc one. lol
I've done alot of these seats, go with the factory fx tall seat foam, with a factory fx tall gripper seat cover for a klx/drx 110. The seat foam is awesome, easy to install with a heavy duty stapler..total cost around 80.00