This product has the following features:
? 鉗頭采用了先進的卡緊機構，在上卸直徑為 2 ?"，3 ½" 兩種油管螺紋時，主、背鉗不需要更換任何零部件，卡緊性能可靠、使用壽命長。
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.