Wireless and battery-powered doorbell and emergency calls

This emergency call system allows, without any battery, to trigger an alarm and an indicator light on the receiver, which is connected to an electrical outlet. The call button is always within reach. Choice of 38 melodies with adjustable volume. Range 100 meters in open field.
At a distance of one meter 80dcb.
Call button dimension (receiver): 7.9 x 4.4 x 3.2 cm.

The image is illustrative