FIELD: agriculture.SUBSTANCE: group of inventions relates to agriculture, in particular to milking equipment. Teat cup assembly liner comprises a mouthpiece defining a teat opening; and a barrel joined to the mouthpiece, and defining a bore and a longitudinal axis aligned with the teat opening. Barrel defines an alignment recess located at a distance in the radial direction from the longitudinal axis of the barrel and configured to interact with a wedge. Teat cup assembly includes a liner, a lower retaining ring, an upper retaining ring and a sleeve. Lower retaining ring is connected to the lower part of the barrel and extends radially outward from the barrel. Upper retaining ring is connected to the lower part of the barrel and extends radially outwardly from the barrel and is located at a distance from the lower retaining ring to form an annular recess cooperating with the sleeve. Upper retaining ring forms an alignment recess, located at a distance and radially from the longitudinal axis of the barrel. Sle
