These are traditional size Schilke mouthpieces that are made with a longer shank for a better fit in tenor and bass trombones having a Remington-style style receiver. These trombones may include vintage Elkhart production of the Conn 8H, 88H, 60H, 62H, 70H, 71H, 72H, 73H and others. The new Generation II Conn 88H trombone with removable leadpipes includes one leadpipe that is tapered to fit this style of mouthpiece, labeled "R" for Remington.
These mouthpieces also fit well in a trombone that feels high in pitch, as this will sit out further than the normal shank style. Getzen 1052FD, 1062FD, 3062AF work well with a long mouthpiece like this.
Other sizes of Schilke large shank mouthpieces can be made to order with the long shank in 60 days.