XO Medium-Large .459 Bore, Silver-Plated Yellow Brass, hand crafted 4.8" B4 bell, Monel pistons, two-piece valve casing, elliptical and rounded tuning slides, pearl inlaid and metal finger buttons, regular and light-action spring sets, standard and weighted bottom valve caps, 1st valve slide thumb saddle, 3rd valve slide throw ring and horizontal stop, XO Series Classic case (KC-XCS)