The Series 9 wireless portable doorbell with range extender, works in perfect harmony with family homes and busy lifestyles. The halo light and LED strobe indicator offers visual alerts, which is ideal for when the doorbell can not be heard. It can be operated from 200 metres range, and offers adjustable maximum volume of 90 decibels which carries up to 1000 metres range. The eight crystal clear voice melodies provide options to choose from, and the batteries offer life up to 5 years. The sleep/mute mode silences the doorbell for 3, 6, 9 or 12 hours, and the choice of 8 digitally enhanced melodies options can be customized by adding your own tune. The doorbell is easy to install and is set up to work straight out of the box. Activlink TM technology offers reliable wireless connectivity, and allows the doorbells to link with door and window sensors or wireless motion sensors to create early alert. Two doorbells can also be linked together to extend wireless range from 2 to 4 metres.