On a one ton’s rear, on either side where the brake line enters the wheel cylinder on the backing plate, there are 2 hex heads. These run through the backing plate and are used to turn the toothed adjuster for the shoes on the inside. In my opinion, these are soooooo much easier to work with than the stupid little hole you have to stick your brake tool/screwdriver in, then fiddle/guess which way to turn to back off.