The Rock 'N Roll Musical Mobile measures 12 inches x 12 inchces x 19 inches and plays the music of Brahms' Lullaby to soothe your baby to sleep. Canopy is made of 100% cotton and plush guitars are 100% polyester. Easy to follow assembly instructions are included. Contains optional wall mount assembly and no batteries needed. Gone are the times of singing lullaby, let a musical mobile fo the trick while you also dance to the tune!