You're better off getting a used old style (one beep) Dytter if you can't afford a ProTrack, ProDytter, etc. The Paralert is big, must be mounted outside the helmet, only beeps once, is not supported by the former manufacturer and I'm not sure you can even get batteries for it anymore (don't know for sure what kind of batteries it takes though). The old Dytter is small, can be mounted anywhere a ProDytter, etc, can mount, only beeps once, has excellent support from the manufacturer and batteries are still available from most of the larger gear dealers.
