LDS4 = inner diameter + .637" or 16.18mm
The LDS Model has a bit more depth to the cup than it's shallower counterparts. In this way the LDS is unique offering a cup, that while still on the shallow side, gives players that extra bit of room for their lips to vibrate freely without bottoming out. This model is truly versatile, offering a massive sound with lots of playability throughout the entire range, low to high. If you've never really been able to play a shallow cup before, this is the one you may want to try! The shorteness of the overall length with the #27 bore (.144 or 3.65mm) combined with a large back bore make this model the most free-blowing lead piece available. If you have been accustomed to playing on mouthpieces that have larger bore sizes, the LD models can offer the same open blow you've come to feel comfortable with and rely on. This set-up is easily the equivalent of a 25 bore with a Symphonic back bore, but with the extra boost for the range and shift in the timbre that a shallow cup can provide, and that is required for lead playing or piccolo work.