Korpa 
The Sennheiser Freeport Wireless System offers a high quality UHF, multi channel wireless system at an incredible price. If you're not familiar with wireless jargon, here are the basics!
UHF stands for Ultra High Frequency - this refers to the type of radio wave that the wireless system transmits on. Older (& sometimes the new but very cheap) wireless systems are still using VHF (Very High Frequency) to transmit on, & these are the types of system that often interfere with local taxi firms & other shortwave radio users.
UHF does not have this problem & provided that you're using a UK licenced frequency (which you will be with a Freeport system) the only interference that is possible is from another UHF wireless system that uses the same frequency (ie - another member of your band!).
Multi Channel means that the wireless system can be switched to work on different frequencies. The Sennhieser Freeport system has 4 frequencies (or channels) to chose from - all of which are UK approved to be used without a licence.
This means you can run 4 Freeport systems simultaneously in the same band - you just each select a unique frequency.
If you need more than 4 wireless systmes then you'll need to buy a more expensive system with more frequencies to chose from (like the Sennheiser Evolution Systems.
In summary, the Freeport system operates on UHF which means virtually no chance of interference, & it has 4 channels to choose from, which means up to 4 people can use Freeport systems in the same band.
The presenter system is sometimes called a lapel system. This is ideal for teachers or other business presentations as the lapel mic that comes with the system is very small & just clips to your clothing.
Here's what Sennheiser say about the Freeport FP12 Wireless Presenter System
The presentation Set ensures maximum speech comprehensibility during lectures, presentations and theater performances. The system includes a bodypack transmitter, a diversity receiver and an inconspicuous clip-on microphone with an omni-directional pick-up pattern.
