Flash key Redial key Mute key Voltage Message Waiting indicator High/medium/low ringer positions Adjustable receiver volume Compatible with Centrex, PBX, or standard telephone services Desk or wall mount Hearing aid compatible Scratch-resistant matte finish Colors: Charcoal and Platinum The 8004 goes beyond the basics to offer added convenience features. The Flash key makes it easy to transfer calls and use custom calling features such as Call Forwarding, Call Waiting, and Three-Way Calling. The Redial key saves time when you need to dial a number repeatedly. And, you'll find the Mute key is a great idea whenever you need a moment's privacy from others on the line. The 8004 also offers message waiting and visual ringing indicators, making it the ideal in-room telephone for universities, hotels, and hospitals. The 8004 also works well by itself - in a lobby, reception area, or busy shipping department. The telephone adapts to any home or office setting. It works with a PBX or with Centrex services, as well as with standard telephone service. Plus, the ringer and receiver volumes are both adjustable - so you can be sure the advantages of the 8004 come through loud and clear in any environment.