Designed with the professional in mind. Secure lock helps prevent blade from creeping. Includes 16" and 19.2" stud center markings. Special Tru-Zero hook does double-duty as a pivot for drawing circles and arcs. Three-rivet, corrosion-resistant hook moves for accurate inside/outside measurements. High-visibility yellow steel blade remains rigid up to 7 ft. and is coated with Mylar for durability. Extra-tough chrome case with belt clip for easy portability.