Flying gently overhead, mobiles are both calming and entertaining for your baby. Our arm is designed to hold a variety of mobiles, so you can switch them whenever you like! DETAILS THAT MATTER Accommodates Pottery Barn Kids cribs with flat railing. Made of solid beech wood. Finish is applied in multi-step process providing durability, depth of color and richness to each piece. Mobiles should be placed well out of arms reach of your baby. Once your baby is able to sit up, mobiles should be removed. KEY PRODUCT POINTS Clamps onto crib railing; railing must be flat. Arm swivels at the base. Pottery Barn Kids exclusive.