Our RF Bracelets will NOT work without the controller in the same area. It works within 300 meters (about 900 feet) inside or outside. RF Bracelets will work within 900 feet of the controller. Best of all these bracelets become light-up bracelets you can take home after the show! Light up your concert, stadium, nightclub, Bar Mitzvah, or party in your choice of colors and flash. Our 433 Hz Radio Frequency Controller is an amazing new technology that allows you to control LED flashing bracelets with the RF Concert Bracelets Controller push of a button! Sold by the individual controller. Please order in increments of 1 controller.