Purchased this to use with my ameda purely yours pump with my son in 2009.  Now with my daughter still using it and absolutely love it.  It's adjustable on size and does stretch out a little in the cup part but I occasionally wash and it takes care of it.  Velcro can come apart when putting on so make sure you adjust to the right size.  I wouldn't use anything else!  Also comes with straps if you want to use but I never used them.