Adult Bed Rails– (Includes bed rails, set of 6-slats, set of center support legs and all the hardware needed to convert your crib into a full size bed.) Unlike most convertible crib companies, we include center support legs to offer families a substantial adult bed conversion as they extend the life and value of their crib. Our full size conversion accommodates a full size mattress. A a full size box springs/mattress foundation is recommended also if converting with both the headboard and footboard from your crib. If using our Low Profile Footboard with your adult rails, there is no need for a box spring. Mattress and mattress foundation are sold separately. Milk Street bed rails turn your crib into that extra bed for a guest or a nanny! Our high back cribs make gorgeous adult beds with rails that offer two height options! Once again, Milk Street furniture is built with love for the life of your child.