as Mr. Waldemar from Wildenstein already wrote, you should inquire whether this unit is compatible with existing base stations. I have it connected to the Fritz! Box 7390 with no problems. Here it is not only fully compatible, you can on the Fritz! Box even build any problems talking, which is only about passing on a "normal" phone is otherwise possible. For incoming calls "ringing" with it (if set) and with a very pleasant tone sequence and you can of course take this conversation directly. I've just clipped on the collar of my home-Smurfs-TShirt. Since it is so small and light, I sometimes forget that I'm wearing it. The caller does not even notice that you can make phone calls using a hands-free device, since there is no echo occurs and it also does not lead to significant interruptions when talking himself. Although the tiny speaker sounds due to design a little squeaky, but the intelligibility is excellent. The fantastic in this device is that it has not only both hands free, but can also move freely in the home and does not have to always remember that take phone. It has also been pinched no device between the cheek and shoulder, where you either conceals the microphone or runs the risk that a fall in the soup that you just stir. Also you need not have anything to put in his ear, which I personally do not like. The clip has been thought as the device itself super. The tiny supplied battery lasted me four and a half hours after the first charge of pure talk time. The charger fits in its dimensions also to the device, ie it is very small and nothing to everywhere. I am always very skeptical about this whole plastic objects, but from the L410 I am absolutely thrilled. In the user manual all functions are adequately explained and the technical data are adhered to. When you connect to a base station should make sure that at this the password sequence "0000" is set. Since it except the combined inputs / off or call-answer / hang-up is no other input options on L410, sets the registration process ahead this pass phrase. This is also so in the manual, but perhaps can be read when this manual only briefly skims (as I do in most cases).