The newborn sling is suggested for use up to 3 months. However, should the child be able to have controlled body movements prior to that (such as rolling), we recommend that you discontinue use of the sling.
The reclining side of the tub can be used until the child has the ability to sit up (an average of 8 months old) Discontinue use of reclining end once child is able to pull up to a sitting position and begin to use the upright toddler seat at opposite end instead.
The tub, in any stage, is recommended for children under 25 pounds. Once the child reaches 25 pounds, we recommend discontinuing use of this tub. It ultimately is up to the parent to gauge their child's development and decide when to move the child between the 3 stages of use.