Abstract: A nipple with an extended sleeve comprises: a suction head; an inner nipple opening at a lower end of the suction head; an air inlet valve enclosed at an edge of the nipple opening; a sleeve extended from an inner side of the air inlet valve; into a milk bottle and integrally formed with the nipple. By above structure, air flowing into nipple from the air inlet valve will flow along the “outer wall” the sleeve to a rear section of the bottle so as to be far away from the bottle opening, but the liquid in the bottle flows out along a liquid supply channel within the sleeve. Thereby, the air inlet path is isolated from the liquid outlet path. Furthermore, an outer surface of a distal end of the sleeve is formed with one of a straight folding flange, an inclined folding flange, and a concave folding flange.

Abstract: An air inlet sleeve of a baby's bottle has a hollow sleeve capable of being installed to an opening of a baby's bottle. An annular neck protrudes from a periphery of the distal end of the sleeve. The annular neck inserts into a lower section of a nipple matched to the baby's bottle and then a cover of the nipple covers and positions the nipple. An annular channel is formed between an inner wall and an outer wall of the sleeve. A bottom of the channel has a plurality of air inlet holes which are arranged around the round bottom. Air entering into the nipple will flow along the annular channel, then output from some of the air inlet holes which has a lower liquid pressure; thereby, as a user sucks the liquid in the baby's bottle, the user will not suck the air.