Sennheiser All-Day Clear Slim: Endorsed by Hearing Care Professionals Clear and vibrant hearing performance: Automatically adjusts to the sound environment around you, providing support for adults with mild to moderate hearing loss All-Day comfort and secure fit: Ensure long-lasting comfort with the unique earbud-style receiver and adjustable forming wire that fits virtually any ear -- ideal for people wearing glasses Seamless Bluetooth connectivity: Built-in BT lets you connect to your iOS or Android smartphone for hands-free calls, music streaming, podcasts, audiobooks and more with just a tap on your phone Easy set-up and customization: Simply set them up in a few minutes using the intuitive app which features personalization options - no audiologist or appointment required Extended battery life: Dependent on individual usage, the rechargeable battery offers up to 21 hours of continuous use, supporting you throughout the day 30-day risk free trial