(4) 360 degree ultra flow screw in style nipples and necessary 1/2 PVC tees for connecting to 1/2 PVC pipe. Each nipple has a 360 degree stainless steel nipple head that the chicken can operate from any angle. 1/2 PVC Tee Is slip to slip on open ends this means you slide your PVC pipe directly into the tee. With this listing you have the freedom to design your own watering system the way you want it and save big by doing it yourself. No experience necessary. Fowl learn to use them fast whether they are a day old or 5 years old.Works great for broilers breeders layers pullets chicks ducks and other game birds.Typically this is what professional chicken farmers use and they use them for many reasons. No poop in water so it is sanitary. No cleaning dirty waterers every few days. The freedom to create a system based on the number of birds you own. No spilling and soaking the bedding/nesting material. Clean fresh water can be ready on demand stored in 5 gallon to 55 gallon storage drums and be gravity fed to your water nipple lines.Manufacturer recommends 1 nipple per three birds. From my experience you can go up or down a few on this number if they can all get a drink when they feel like it. It is optimum at 3 or less per bird to avoid lines and arguments if you let them out where the water is every morning.Water nipples work under low pressure (5 psi or less) and must be mounted vertical (straight up and down). If you are attaching nipples to PVC pipe the water needs to be gravity fed. If you are wanting to connect it directly to a garden hose (house pressure) you will need a pressure regulator to regulate the pressure down. House pressure can be 30 to 70 pounds of pressure you would need to regulate it down to 5 or less. If you are wanting to hook your water system to garden hose pressure that is fine but you will need a regulator in order for you to do so. We sell the regulator for reducing the pressure in our store.