Stanley FMHT33706 FatMax Keychain Tape Rule has a 3ft blade x 1/2" width. The keychain feature makes this tape quite handy to carry with you and have available everywhere you go, and the FatMax brand features insure durability and long life. The Tru-Zero end hook allows for accurate measurements for both inside and outside measurements, and the Slide Lock holds the blade securely in position. This tape is protected by a high-impact ABS case with durable rubber for comfort, which also holds up to heavy use. This tape features 16" and 19.2" stud center markings to help you easily identify stud centers. The key ring provides an element of handy convenience which allows you to have this tape available for almost any use!