The manufacturer recommends 3 birds per nipple No drip cup required. The working pressure should be reduced to 1 PSI. Screw directly into the PVC pipe, or use the reduced ball hole of PTFE tape to fix the PVC pipe. POM body, 360 degree side action pin. description: The chick nipple can put a drop of water while pressing the nipple. specification: Weight: 8.5 grams per assembled colour: red + silver Material: Plastic size: Length 52mm Package Contents: 50 * chicken water nipples Instructions and precautions: 1. Use a drill with a diameter of 11/32 inches, suitable for thick plastic wall PVC, barrels or containers. 2. If you want to use plastic water bottle caps, it is recommended to use a drill bit size of 1.59 cm. 3. Using a little silicone or tape, screw the nipple into the hole. 4. The manufacturer recommends 1 for 2~3 birds. 5. The faucet only works at low pressure (5.5 psi or less). Note: Do not connect directly to garden hoses (indoor water pressure is about 30 to 75 psi). If you want to connect it directly to a garden hose, you need a water pressure regulator. Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.