Each package contains 3 pairs of closed sleeves. It is available in small size. It can be adapted to fit most ears and hearing needs. They are easy to replace on the hearing aids and can be adapted to fit most ears and hearing needs. The vented sleeve design allows more sounds through the OTC Hearing Aid which helps reduce the uncomfortable feeling of plugged ears. The Sony CRE-S2VX Vented Sleeve for CRE-C20 Self-Fitting OTC Hearing Aid provides balanced sound quality supporting the performance of the C20 OTC hearing aids.