This hard rubber mouthpiece has a brass ring on the inside shank which makes the large shank actually fit on modern neck corks! It has a tip opening of 0.053″, a rollover baffle, slightly curved sidewalls and a small-medium chamber. This is a very rare and desirable soprano mouthpiece in my book. I love Woodwind Co soprano pieces, but you almost never see them for sale. And with the shank modification, it actually fits your cork without trouble!