This is part of ISM and it's a fairly common frequency for low power tx/rx modules http://www.google.com/search?q=433.92+MHz&ie=utf-8&oe=utf-8 http://www.googl

This is part of ISM and it's a fairly common frequency for low power tx/rx modules http://www.google.com/search?q=433.92+MHz&ie=utf-8&oe=utf-8 http://www.google.com/search?q=433.92+MHz&ie=utf-8&o... Even car keys operate around this frequency.