These mouthpieces have the same design as the standard C series mouthpiece but with a 18mm diameter. They are also available in different cup depths. The M is a medium deep cup used on the original C12 mouthpiece and the S cup is a shallow cup used on the original C15 mouthpiece. So, a CMB8 has a medium deep cup, an 18mm inner diameter, and a #8 bore size and so on.

We will be stocking 8's,10's and 12's in medium and stock cups but we'll be happy to order any size you require.