Sign up for an Award
Participate with your entry in one of our professional or student awards.Sign up for an award
You are using an outdated browser. Please upgrade your browser to improve your experience.
Warning mark ruler: when the heavy rain,the water reaches a certain degree,is beyond the buoyancy, concealed in the manhole cover of warning feet will float out ,which makes people quickly find manhole covers, Put the lid on crossing beside the water can play a warning role, also can measure the depth of the water.
Guangdong Industry Technical College