The NMDRXDB is a high-performance doorbell solution for deaf and hard of hearing, also useful for noisy environments. The portable chime has Ultra-Bright high power flashing LED’s combined with an extra-loud chime when the wireless doorbell button is pressed. There is a vibrating pillow pad output socket for the Medpage vibrating pad. VIB-PAD. Multiple doorbell buttons can be used (up to 5) each activating different coloured lights (front door back door etc). Selectable LED colours to identify transmitter device Multiple active alarm indication - selected transmitter colours ?ash alternately until alarms are cancelled Powered by 3 x AAA batteries Dimensions: H 80mm W 68mm D 38mm Optional mains AC power adaptor Compatible with all Easylink/Medpage transmitters Quick and easy to set up and use 3-level alarm tone volume switch (up to 96dB) Latched or timed alarm duration (continuous or 30 seconds) Power/signal/battery status LED Output for vibrating pad to aid deaf people Frequency 433.92 MHz (FSK) Long range capability Vibrating pad output 3v @ 300ma via 3.5mm jack socket Top focusing lens high intensity ceiling projecting LED’s On/off top light selection switchPrice includes batteries