♬With adjustable reflective lanyard, light and sturdy, easy to carry, whistles is suitable for personally families and teams. ♬emergencies whistles are make of ABS, which is very light, sturdy and stable, not easy to break or cracks, and can be used for a long time. ♬With the double tube designs, each whistles with lanyard can emit high and low frequency sounds, which can generate sound power as high as 120 , enough to be hear from a mile away. ♬emergencies whistles can be hear from far away, and can be used for sailing, hiking, boating, kayaking, camping, , emergencies. ♬With the adjustable buckle, the length can be adjusted at will, whistles can be easily tied to backpacks, sailboats and coamings.