No one has mentioned this so I thought I'd jump up on the soap box for a minute: First: Why--does Medela keep changing their kits? I'm sure some engineer has a good reason (probably to keep his/her job), but honestly if it ain't broke don't fix it! Secondly--Why would a company who appears to make the majority of its capital from pump rentals--sell a pump for $20 more than a 5 month rental?? Is that flawed logic or just plain crazy? I have a total of 22 pumps-- from both companies-- and 18 are sitting here. I'm a flat rate station and the overhead is killing me!! Mom's a buying the PnS pump through baby stores and other rental stations. By the way 2 of my rentals are from gals who bought a PnS and claim it doesn't work. Sorry but I had to get this off my chest- Climbing down---next Marie Davis