In this schematic the "Cushion(11.5x22x20)" is used most often.
Parts such as the Seat Tail Box (model W): Box Assy,seat Tail(blue), Tape Set,box Seat Tail(white), Box,seat Tail (black), Cushion(11.5x22x20) are included in the Gsxr750 1998 (w) (e02 E04 E18 E22 E24 E25 E34 E39) Seat Tail Box (model W) parts fiche.
The Suzuki SEAT TAIL BOX (MODEL W) has six products enlisted in the schematic.