Tenor Trombone Large Shank Mouthpieces(International customers may be subject to import duties and taxes.) If this item is not currently in stock, the lead time is typically around 12 weeks. Size Cup Throat Notes L4 26. 0mm 7. 2mm L4 1 2 25. 8mm 7. 1mm L4 B. B 26. 0mm 7. 1mm Designed with Brett Baker. Shallower cup than the L4 and also a slightly flatter rim. Many players find this model to be very similar to the classic Mount Vernon 4G. L5 25. 5mm 7. 0mm L5 B. B 25. 5mm 7. 0mm Designed