Personalized Trombone Music Marching Band Newborn Layette. This fun trombone design makes a great gift for the aspiring trombone player or trombonist. 100% combed ringspun cotton 5.8 ounce 1×1 baby rib sleeper. 3/8" flatlock binding at envelope neck and cuffs. Back sleeve flap to protect hands. Elastic opening at bottom. Infant: 0-3 Months