Panasonic KX-TGD212N - cordless phone with caller ID/call waiting + additional handset

Intelligent eco mode automatically lowers the power consumption when you're using the handset close to the base unit. Not only does it extend the available talk time, it's good for the environment. When less power is used by the handset to communicate with the base unit, battery life is prolonged which results in less frequent charging and can result in fewer batteries in landfills.