The HR* CUSTOM DARK series is our premium line of hard rubber saxophone mouthpieces. In order to achieve our goal of making the most beautiful sounding and playing mouthpiece possible, we started with our proprietary Chedeville® Rubber. The CHR (Chedeville Rubber) is the finest material used in hard rubber mouthpieces today and is a softer purer formula than regular standard hard rubber. It imparts a beautiful, rich, warm sound to the HR* CUSTOM DARK series making them the favorites of today's leading traditional and contemporary players alike. This is one of the most popular and best sounding mouthpieces for sopranos on the market.