CALF BOTTLE RING ONLY SCREW-ON, Super-Calf Nipples feature an air release valve to ensure proper flow of milk to nursing calf. These bottles and nipples were designed to work together to more effectively position the nipple, for less struggle and wasted time. Easy-clean lip allows producers to quickly, thoroughly clean and sanitize bottle to prevent bacteria build-up. Available in Snap-on and Screw-on styles.