... , and 2 7/8"- 4½" tubing and 4½"-5½" casing of a dynamic open-clamp . It has the following features: 1 ... structure. 2, Lord, forceps are used in the dorsal surface of clamping rollers climbing, cards tight, reliable and timely release. 3, the ... or string. 5, friction braking institutions in the clamp heads of the adjustment, maintenance more convenient. 6, and reset manually reversing ...