Water Ring Hydraulic Radial Artery Compression Device is a new concept hemostatsis compressor specially designed for puncture site management after radial catheterization.Water Ring a water balloon ,which procides a crystal vision on the puncture site. The puncture incision and the surrounding tissue can be observed in real time. Water Ring is integrated with a hydraulic system. It frees from the traditional method that connecting with a syring.With the facilitated pressure control,physicians can easily achieve degressive pressure,so as to reduce the risk of radial artery complications.