Everything you need to make measuring easier and more exact! The 3-Pc. Measuring Accessory Set includes: 1: the MagnaTip™ Magnetic Tape Measure Attachment: The magnet sticks to any metal object or use the built-in tabs to hold edges for easy one-person measuring. A must for carpenters, electricians, or any tradesman who uses a tape measure. 2: the Square Check: This simple accessory prevents your tape measure from slipping off the corner while measuring diagonals. 3: the EZ-Mark Line Cords: A quick, easy way of marking or identifying the location of shelves and internal construction components; includes three elastic cords: 10'', 20'' and 30''.