ATH-CKS50TW truly wireless headphones combine advanced acoustic technology for stunning bass with a comfortable and secure fit, while a high-capacity battery provides up to 20 hours of powerful, continuous audio (up to 50 hours with the charging case). The newly developed large-diameter drivers (9mm Solid Bass HD TWS drivers) deliver deep bass while the CKS50TW shape provides a snug fit - an important factor for truly wireless headphones as the airtight fit prevents the bass from escaping. ATH-CKS50TW wireless earbuds are designed for reliable, stress-free operation. The left button adjusts the volume and switches between hear-through and noise-cancelling functions, while the right button lets you easily start/stop playback, skip between songs, or enable quick hear-through. The splash-proof design keeps your earbuds dry in sudden rain showers or when exercising.