These small AKG vocal wireless mics are great for quite a lot of small scale applications, such as speach and karaoke. Decent range for most medium sized venues, could work outdoors, if the receiver is close to the preformers.
These should however be used with care, as they have a plastic case. They are not steel and thus, does not handle drops and shocks well.
They also have a tendency to pick up noises from the preformer handling it, such as moving it around to fast(wind noise), switching hands(thuds) and the like.
The on/off/mute on the mic is good enough, although I'd rather have a seperate mute button. Turning it on/off produces a notable pop on the speakers, while mute doesn't, but trying to get preformers to do that is rather hard with this kind of switch.
All in all, decent set of wireless mics for the price. Works great for speach, but I wouldn't recommend it for anything else.