Posted By Stephen Clark My understanding is that if a truck can overturn greater than 90 degrees then it requires a ROPS Roll Over Protection System. This will include a seat belt. Manufacturers will tell you that the truck mast will prevent this however, where trucks are used on terrain or environments where slopes, working on vehicles/ramps can happen then they could exceed the 90 degrees so ROPS would be needed. I always go by the rule that counterbalance trucks have them and reach trucks do not, as the former are generally also used outside whereas the latter are exclusively used inside. This view has been confirmed to me by enforcing officers many times. Hope this helps. PS theres no point fitting them if you don't get the operators to use them, that's the hard part. You should always confirm anything you get from the forum with an authoritative source, including this advice. I suggest you contact BITA British Industrial Trucks Association. Good luck