The GAPCAP availble for alto or tenor sax is The ultimate sax care cap. Fits any saxophone in any case perfectly! By ensureing a perfect fit in case it helps protect from impact damage and allows air dry the sax. Flex wall design fits any model saxophone and is a shock absorber from impact. The top and side vents increase airflow to decrease bacteria growth in the body. Expands at the top to fit any case for safer travel.