1.One Step Cap tightening. The 4STM spinal system of cap is designed with speedy and strong cap tightening process. Surgeon can save unnecessary operation time and do strong & safe screw fixation. 2.Versatility. Surgen can choose Monoaxial screw,Polyaxial and Long arm scerw. The angulation of Polyaxial screw is 34 degree.

The provides three dimensional adjustability to significantly reduce undue stress on the anatomy. 3.Strong Fixation. The screw head is tapered with 3.6 degree. This angle helps to prevent pulling out the cap after tightening it.