Wall Mountable No room on your desk? Then mount the KX-TS500MX right on the wall, and enjoy its convenient features without giving up a lot of desk space. Last Number Redial This dials the number you most recently dialed. If you need to make a follow-up call or the line was busy the first time, just press the redial button. Timed Flash This function, which supports Call Waiting and PBX use, ensures that a caller is not accidentally cut off while on hold. Electronic Volume Control Even in mid-conversation, you can adjust the receiving volume of the handset to any of 6 levels. 3-Step Ringer Selector The ringer volume can be set to Off, Low, or High. Set it to Off when you donâ€™t want to be disturbed during a meeting. Switchable Tone/Pulse Settings The KX-TS500MX can be switched between tone (pushbutton) and pulse (rotary), ensuring that it will work on either type of telephone line.