The Mitchell Lurie Bb Clarinet Reeds, Strength 3.5 are great reeds for an advancing student. These reeds are unfiled and have a thinner tip which helps the reed to respond with ease and has a thicker spine. This reed is more resistant for the student who knows how to play well and gives a warm sound. It has optical laser measurements that make sure these reeds are accurate. These reeds come in a 10 pack!