Sadev (GKN) Mk3 racer outer CV boot

[Grats]

Hi anyone know what the outer CV boot is off on the Clio 3 racer. I understand the Sadev shafts / joints are actually made by GKN motorsport division but just trying to find out what the boots are off, can't imagine they are specials must be some van or 4 x 4. They are 90 and 28mm diameter.

Thanks