Excerpt: The Clarity ClarityLife C900 is a slider phone designed for seniors, with large, easy-to-press buttons, emergency features, a built-in flashlight and the option to use AA batteries instead of the included rechargeable battery. Clarity is a division of Plantronics, best known for its Bluetooth headsets. The C900 is an unlocked GSM phone, meaning it will work with T-Mobile or AT&T, and no contract is required.
Pros: Unlocked, Good call quality and loud volume, Built-in flashlight and emergency features, Can use AA or rechargeable batteries
Cons: 2.5 hours talk time (rated), Keys can be hard to press, Interface could be simpler