Pressure control arrangement for a milk collection system

A pressure control arrangement for a milk extraction system comprising:

• a body having a portion for placing over a nipple of a user thereby to form a milk extraction chamber, wherein at least a part of the body is elastically deformable such that a volume of, or a volume in fluid communication with, the milk extraction chamber can be reduced by manually deforming the at least part of the body thereby to create an under-pressure within the milk extraction chamber,
• characterized in that the elastically deformable part of the body comprises a deformation feature at which the body preferentially deforms when the body transitions between a rest state and a deformed state, wherein the body is configured to retain the deformed state when an under-pressure within the milk extraction chamber exceeds a threshold under-pressure, and wherein transitions between the rest state and the deformed state comprise a predetermined visually and/or audibly and/or haptically identifiable change in shape of the body.