Builder's block line corner anchor bracket

thingiverse

An anchor bracket for the top corner of a brick or concrete block, which can be used at both ends of a block wall to ensure it's level. Simply run a builder's line or string between the two end brackets, once the end blocks have been placed in mortar, and all your other blocks in between can be aligned to the string. You'll need to print two brackets, and mirror one of them so you have opposite left and right corners. No print supports are required.