Do I have to fasten the mattress to the red hooks? Emily M. 01 September 2022 20:08 We recommend that you use the hooks for the best possible safety. Related articles What is the difference between the past versions of the Travel Crib Light and the new one with mesh fabric? Is there a maximum weight for the Travel Crib Light? How do I set up the BABYBJÖRN Travel Crib Light? Is the material in the travel crib safe for my baby? Comments 0 comments Article is closed for comments.