The IST P1-2 Universal Replacement Valve is a reliable and easy-to-install solution designed to restore functionality to a variety of dive gear. Compatible with multiple IST snorkels and masks, including models SN1, SN20, SN26, SN50, M11, and M12, this replacement valve ensures a secure fit and consistent performance. It's an ideal backup or replacement part for maintaining the safety and comfort of your snorkeling or diving equipment.