Patent ID: 8117990

Claim:
A nipple for the suckling of liquid by a baby animal or young animal, the nipple comprising: a base; an upper end; a vertically extending barrel extending upward from the base and downward from the upper end and including a downward extending wall; and a common interior cavity formed by a flexible wall forming the vertically extending barrel and the upper end, the upper end having a horizontal flat central portion surrounded by a periphery, the flat central portion having a pair of slits forming an X shaped pattern, a diameter of the flat central portion being no more than 25% of an inner diameter of the vertically extending barrel, a thickness of the horizontal flat portion being between 5% and 10% less than a thickness of the downward extending wall, the periphery surrounding the horizontal flat central portion curving downward on a radius and extending vertically downward until merging with the vertically extending barrel.