BT Engineering Timber Clamp used at the top of profile
A nifty gadget for setting profiles plumb.
Tighten centre clamp onto profile, then rest timbers onto the two other clamps.
Adjust profile with level, then tighten screws.
Will hold timbers from 76×76 to 38×38 square or rectangle.
Does not take up room in the truck.
Easy, one man operation.