Different nipple for different demands; nipple with 360 degree drinking position, and double safety structure to prevent water leaking; external part of nipple is made of engineering plastic, internal part is made of SS steel, to guarantee more than 10 years life time; square PVC tube to ensure a solid and accurate position of nipple; galvanized support pipe to make the same level of the nipple line; variable nipple spacing: 10/12/15 nipples per 3m, or 16 nipples per 4m. or customized; manual winch or auto winch to adjust the height of nipple line; auto observation and alarm of water level; auto flushing of nipple line.