Class A Flawed blanks include blanks that have an inner diameter slightly larger than 5/8″. These blanks could still be drilled out to be used for other types of calls. Class B Flawed blanks have minor flaws, may be shorter than 3″ lengths. These could be used for practice or low quality calls. Class C Flawed blanks have major flaws including air bubbles, chunks missing, missized or misshapen. These blanks could be used for practice but most likely are no good for making a finished call. Cracked Inserts have minor cracks in the bell area. Depending on the shape of your insert, the crack may not affect the insert at all. Most are minor enough that they would be turned out anyways. Bubbled inserts have minor bubbles with the potential for larger bubbles. They may or may not cause issues with a finished call. These blanks are sold as-is with no warranty against breakage during turning or shipping and no returns. They are considered okay for practice or special products but not considered high quality enough to be sold as standard blanks.