Doc's Proplugs Vented With Leash are used as a protective ear plug for swimming, surfing, kayaking, and diving. They keep water out but let sound in! Doc's Proplugs help prevent swimmer's ear like an antiseptic. They warm the ear canal preventing surfer's ear. Surface tension at Scott's Vent helps keep cold water, wind and dirty water out. They shield the ear canal structure from impaction of wax and water.