Make of silicone materials, which have good elastics wear-resistance and enduring Suitable for Scubas diving. Edges of particles, nonslip. It have good sealing and none leakage Suitable for diving, vacation, training, swimming, increasing the funny of diving Easy to connecting to and remove from pipe. Suitable for most ordinary diving snorkeling and regulators Comfortable and easy to bites. to carry and not occupy too much storage space