Yurbuds Ironman Inspire Blue In-Ear Earbud Sport Headphones with TwistLock Technology Earphones, Sweat Resistant, Cobalt Twistlock Technology: Yurbuds TwistLock into place for a secure fit that never falls out, even under the most intense workout conditions. Sweat + Water Resistance: Developed for training in any conditions. IPX 5 Rating available on Venture Pro, Explore Pro, Venture Talk, Explore Talk, and Venture Duro. Ambient Noise Awareness: Designed to allow more ambient noise than most other earphones at the same volume levels. Exceptional Sound Quality: Clinically proven acoustics for deeper, richer sound. Flexsoft: Ergonomically designed to avoid nerve rich areas of the ear. Made with flexible silicone, Yurbuds are ultra soft and comfortable for hours on end.