The Self Lock Series of tape measures is a unique line of tape measures. The series features 12-foot x 5/8-inch, 16-foot x 3/4-inch, 16-foot x 1-inch, 25-foot x 1-inch, 25-foot x 1-inch inch/Engineer scale. The Self Lock Series features a unique self locking mechanism that allows the blade to extend smoothly as well as a push button release that insures complete control when retracting the blade. This is the ideal measuring tool for anyone from the do it yourself-er to a professional tradesmen. The series also provides an impact resistant rubberized case and a nylon coated blade for maximum durability.