These custom cut bed slats can provide extra support for your sleeping needs! Just measure the width of your bed frame, in three spots, the head/middle/foot, prior to purchasing your slats. Allow 1/4" play on either side of the bed frame when measuring.  They lay on your bed frame, underneath your box spring and mattress, and are held together with a fabric material to keep the slats in position.  The slats alone are not designed to support just a mattress but add to the support of your mattress and box spring. If you don't see the size you need for your bed, please contact us and we will be happy to see if we can meet your specific request. Custom made in the U.S.A.!