No need to use a builder's square or chalk box; using the peel and stick backing, simply attach SquareNTape™ to any standard tape measure (sold separately) then slide and mark your board with the 8-in-1 SquareNTape™ from FastCap®! SquareNTape™ features include a 90° squared edge that lets you lay it across a board for 90° squaring capabilities. Notches at 1-1/2" and 3-1/2" make it easy to mark 2" x 2" and 2" x 4"s out of wide construction boards. Made in USA.