Plantronics' CT12 2.4 GHz DSS Cordless Headset Telephone (analog, single-line) is an ultra-compact single-line telephone, offering hands-free convenience and comfort. Includes convertible 2 in 1 headset for over-the-head stability or over-the-ear convenience, a noise-canceling microphone for superior sound clarity and FireflyÖ, the unique in-use indicator light that lets others know you are on the phone, Features Include: Pocket Size: Ultra-compact remote unit fits in the palm of your hand and features a convenient belt/clothing clip that remains attached even while charging. 2.4GHz Digital Technology: For increased calling range and digital security.FireflyÖ In-use indicator light lets others know you are on the phone.Noise-canceling microphone eliminates background noise.Caller ID Ready/Call Waiting display: On the remote unit, lets you see who's calling.Extended Talk/Standby Time: 5.5 hour continuous talk time and 10 day standby.