anti-collision monitor hydrant of the two stage relief the pressure have introduce the technology retains the advantages of the same kind of foreign products, and improves the key components, more practical, and get national patents. its performance is better than traditional fire hydrants, such as the maintain pressure of 1.0, when emergency use it, open use your hands. it’s not easy to open even turn the switch handle. this product can flexibly and quickly open and close in any case.