These are used to fit the pedal box to the floor pan. You will need to cut a 21mm hole in the floor pan insert the top hat and weld around the top. This will give you 6 secure fixing points to bolt the pedal box to. Remember to use large spreader plates to spread the stress on the pedal box fixings. The thread of these parts are M8. Simply dry fit your obp Motorsports Bias Brake Pedal System and position to suit, mark / scribe the Pedal Box Assembly hole positions onto your floor pan. Then accurately cut a 21mm hole in the floor pan where you have marked / scribed. Insert the top hat and weld around the top. Complete all the fixings and you are ready to hard fit you pedal assembly ready for all the fluid line connections, Accelerator etc. You will soon be ready to get back out on the track.