A friend of mine has a rat rack that a pet store gave to him. It came with ONE of the fittings pictured below. Its for the rats drinking water, you move that little stem allowing water to come out. I asked some mechanical people here at work but of course they didnt know what it was, said it was too small lol (We engineer and design power plants). I was hoping that some of you who have rat racks would be able to tell me what its called and where it can be bought. Yes I told him to try the hardware store, apparently he did but I dont see why they wouldnt have it. I also told him to contact the petstore to ask them where they got it. Im not sure if he has or not, I haven't heard back from him yet. Even if you dont know what it is, maybe tell me what you used for this purpose? He already has the tubing and water jug set up on the rack he just needs something to regulate the water flow. Thanks!