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. SquareNTape™ also has marks at 1-1/2'' and 3'' for laying out plates for single and double stud layouts; perfect for window and door construction. Marks at 45° and 22-1/2° make it easier to mark angled lines, plus, it has a handy erasable notepad for writing down measurements. Made in USA.