Bach 3516 Silver Plated 6 Cup Trumpet Mouthpiece, Deep Model No. / Depth of Cup / Approx. Cup Dia. / Rim Shape / Description 1* / Deep / 17.50 mm / Medium thin. / Extra-large cup for players with a robust embouchure. Produces a great volume of tone. 1X / Deep / 17.00 mm / Medium wide. / The pre-1970 (old style) No. 1, with slightly smaller cup and wider rim than the present model. 1B / Medium deep / 17.00 mm / Medium wide. / Large cup for players with a robust embouchure. Produces a warm tone with great volume. 1C* / Medium / 17.00 mm / Medium wide. / Large diameter, medium cup  good for all-around use.