Customers say these replacement parts fit their pumps snugly and work smoothly with various models. Many reviews mention easy installation and cleaning. While some note the parts feel different from originals - with a few finding them slightly looser or tighter - most report they function well for daily use. The sizing options get lots of love, though several point out it's just one piece per order. A handful of users mention suction issues or fit concerns, but the majority find these parts work just as well as (and sometimes better than!) their original equipment. Frequent comments address the straightforward cleaning process and durability during regular use. Users particularly appreciate having backup parts for their pumping routines. Some wish the product description was clearer about quantity, but most are happy campers with their purchase. The convenience factor gets major props from busy users who can keep their pumping schedule on track with these handy replacements!