Well what can I say no whistles no bells but they work, in fact to use an English expression "They do what it says on the tin" Not everyone has a large budget and I got these for a small theatre group who couldn't afford or need LED displays with lots of indicators E.T.C. On these units you just get indicator LEDs for On, Transmit and audio, I bought the guitar version (which is the same as the mic version) because you don't have to pay for a mic which might not suit you, any mic with the mini XLR AKG connector intended for radio mics will work. There are sixteen frequencies available so I just used the first 4 and had no problems. Thomann advised me that you can only use four units together but I suspect you could use more because the frequency spacing seems more than adequate but Please Please double check this before you take my word because there are other issues like frequencies being legal in your country. All in all great little units, I was using them with other makes at the same time with no noticeable difference.