What a great little pack and well worth the money, my son at 12 weeks had no problem switching between his previous bottles (breastflow - the faster flow teats were out of stock everywhere!), the breast and these mam teats. I expected lots of crying complaints when I switched to the mam bottles but there was none - he loved them right from the start. I also found the self sterilisation instructions very easy to follow. To top the pack off they include a great little dummy, my son has always hated sucking one, we tried several, I thought I'd try this new one after his 12 week jabs - he loved it! In summary: great product and well worth the money.