Why don’t you sell Grobags to last my baby for longer – e.g. from 6 month to 3 years?

Babies do a great deal of growing between 6 months and 3 years and we don’t believe that it would be responsible to try to manufacture a Baby Sleep Bag that would fit, and be safe for, both a 6 month old baby and a 3 year old toddler. Babies grow at the greatest rate in their first 6 months of life, and then their rate of growth slows down gradually. This is why our youngest size Grobag (0-6m) lasts for 6 months, our next size up (6-18m) lasts for a whole year, and our third size up (18-36m) lasts for a full 1½ years.