Jupiter 4 Valve Professional XO Model Bb Euphonium 1270L. XO Model Compensating 4 valve (3 Top Action + 1 Left Hand) Upright 12.2" bell Lacquered Brass Body stainless steel pistons .590" bore (4th valve .630"-.660") bore rose brass mouthpipe ABS molded case. The Jupiter 1270 XO Series Compensating Euphonium is designed to meet the performance needs of the pro-level player. The 1270 XO Series features a .590-.660-inch graduated bore with a compensating valve system and 12.2-inch yellow brass bell. The Jupiter 1270 XO Series Compensating Euphonium includes an ABS wood frame hybrid case and mouthpiece and is available in lacquer (1270L) or silver (1270S) finish.