Dilini, are you  a member of the UK CAH Support Group?  In their latest newsletter there is a very interesting article all about the pump and what is has done to help a young lad with CAH. The article is very comprehensive and explains how it works and features a picture of the pump. If you are not a member, I would recommend joining, it is a brilliant group, it offers excellent support as well as the newsletters which are full of interesting information.