The Roll-By is a 300 mmHg Aneroid instrument for mobile use. Cat No. 1170 (as shown) includes the Adult, Child/Small Adult and Large Arm Calibrated V-Lok inflation systems, 8 feet of Extendex tubing, large integral storage basket, and die-cast aluminum wheel base and cast iron weight for increased stability. It's built to agree with our master instruments, which are traceable to the United States National Institute of Standards and Technology. It complies with ANSI/AAMI SP-9 for accuracy and performance (1% full scale 3 mmHg). The unique, low reflection, high contrast scale and red pointer increase visibility and reduce parallax error. They are manufactured with a precision low friction movement and twin pre-seasoned phosphor bronze diaphragm capsules.