This product has the following features:
钳头采用了先进的卡紧机构，在上卸直径为 2 ⅞"，3 ½" 两种油管螺纹时，主、背钳不需要更换任何零部件，卡紧性能可靠、使用寿命长。
The tong head uses inner curved roller climbing and clipping mechanism and needn’t to change any part during making up or breaking out the tubing thread which diameter is 2 7/8 ″or 31/2″.
Two shifts provides high speed at the high gear and large torque at the low gear.
The brake mechanism is on the upper and so it is easy to adjust and repair.
The new type hydraulic Backup tong and master tong form a combined tong . Operating the manual control valve of master tong, the combined tong clipping and unloosing simultaneously.
The adequate torque will be gained during making up and breaking out the various steel tube by adjusting pressure of oil .
This product has owned several patents of China.