The present invention relates the field of mother and baby products, in particular to a breast pump and components thereof. The tee joint component is different from others in that the tee joint component is only provided with one negative pressure input interface a milking shield and a milk outflow end disposed on the tee joint component are both integrated with the body of the tee joint component the milk outflow end is a V-shaped one-way valve the whole tee joint component is made of a flexible material. The cross-sectional thickness of both ends is greater than that of the middle region of the tee joint component. The flexible material is food-grade silicone rubber.
