Wireless pushbutton tracker with battery (lifetime 5-8 years). 55 x 44 mm, 15 mm high, anthracite/blue. Weighs only 20 grams. Smart Home sensor.
The wireless pushbutton tracker has a blue pushbutton to send normal pushbutton telegrams.
After opening the housing (grasp into the joint and prise apart), switch the tracker on by shifting the slide switch to the Tr position.
The sensor then sends a presence telegram every 60 seconds.
An internal 3 V button cell CR2032 supplies power for several years.