As babies are so unique there is no ‘should’ set age. Watch your baby/child and trust yourself with what you observe. If your baby seems happy, relaxed, comfortable, cosy, contented and is ‘sleeping like a baby’ then let your baby/child decide when they have had enough.
Most mothers, in our experience like to use the Sleepwrap for safer sleeping from bassinet or hammock to cot/crib and then the transition from the cot/crib to the ‘big bed’.
The usual age that babies/toddlers seem to like the comfort and security of the Sleepwrap is from approximately newborn to two or three years of age.
However, for boaties the Sleepwrap’s are used for children up to 6-7years of age. See: http://www.safetsleep.com/boating/
“As the designer and developer of the Safe T Sleep Sleepwrap all my three children were safely able to ‘move on up to the big bed’, at fifteen months with their Sleepwrap without fear of them creeping, rolling or falling. My eldest son was just over two years old and my other son just under two years old when they were happy to sleep without their Sleepwrap. My daughter, at age three and a half, on the other hand, loved her Sleepwrap so much that she would put it on and off herself. With her I just pretended the Sleepwrap was in the wash and still wet for three weeks. After this she forgot about the Sleepwrap and this seemed a gentle way of weaning her out of the Sleepwrap. Although I need not have worried as people with boats, including the last two America’s Cup families used the Sleepwrap with their babies on their boats from newborn up to seven years of age”. J see http://www.safetsleep.com/pages/facebook-reviews