Tillett B7 XL Racing Seat with Edges OnThe B7 XL is a lightweight, high specification version of the B6 Screamer XL. It has the narrowest dimensions of any FIA 8855 1999 homologated seat and at 3. 7 kg also the lightest available to the best of Tilletts knowledge. This is the B7 47 version, which has a maximum width of 47cm. The seats can be ordered with Dinamica panels as an option, which adds 1 kg. There are four bracket options to use for installing the seat: TB FIA mounting brackets