They come supplied with 'screw-type bolts', meaning that you have to thread the hole for it, but you don't need to put a nut on the end. No need for sealant.

you also need to modify the heater motor airbox (big black thing at the back of the engine bay with a rubber seal on it) as the brace squashes the front right corner (behind the master cylinder) slightly & then the seal doesn't fit properly over the vented part of the rear bonnet.