The AVENT bottles are very good qualities in general. However, this is complicated washing (for those who do not have a dishwasher) there is a ring platic every bottle that seals between the nipple and bottle ... What idea?!? ! E tells you the hassle to find these rings in the dishes! This is quite "boring" wash these bottles so I recommend instead the "naturals" which are tight and are in 2 pieces only!