The JTU1020 features a traditional 3+1 valve design with 3 top action valves and an angled left hand 4th valve. It also features stainless steel pistons and rose brass mouthpipe. 15" bell, 0.689" bore while 4th valve in 0.748" bore. FEATURES: Lacquered Brass Body is produced using state of the art technology to ensure an instrument of the most accurate scale and playability Stainless Steel Pistons have remarkably smooth, fast action for improved agility and playability The Wood-Frame Case with Wheels boasts a classic look that offers excellent instrument protection whether home or on the road