The Brass Stopcock is a threaded piece of metal used to shut off a water supply. It is a long, cylindrical, and has a series of small holes along its length. The brass stopcock is used to shut off the water supply to a pipe or faucet by threading it into the outlet pipe. The brass stopcock allows water to pass through it and then it allows the water to flow back out of the faucet. The brass stopcock is made of brass and it is used to control water flow in many different applications.