Tillett W4 Black GRP Race Car Seat with BackframeThe W4 is a 25 mm wider handmade version of the W3, which is a reclined seat with a formula race car driving position. This is the black GRP version with a backframe which makes it easily floor mountable with the M8 mounting bolts moulded into the seat. With the backframe the seat is self supporting and easy to mount rigidly to the floor or on top of the Tillett TR1 seat adjustment runners. Seat belt harness holes are included. A five or six point