BT Engineering Dori Block UBDL Long Sided

The improved version of BT’s famous Dori Block! The corner brick sits snug against the profile and the longer side of the Dori Block, making the first brick sit exactly flush with the string line. Engineered to hold two string lines running both ways on 50.8mm profiles. You can use the same Long Sided Dori Block to lay the first brick and run stringline both ways by just turning it over!