1, 35 songs selectable 2, Volume control 3, Range more than 100 meters 2 4, SMT NEW TECHNOLOGY 5, Easy Installation Special Features ... and Down switch, make you enjoy.4) 3 segment volume selection.5) Easy instillation, no wiring needed, no labour involved. (wireless doorbell)6 ... go on24-26, Russian Music27-35, Arabia Music T-6 wireless communication remote control doorbell