Eltako Wireless pushbutton tracker, without wire FTTB

Wireless pushbutton tracker with battery (lifetime 5-8 years). 55 x 44 mm, 15 mm high. Weighs only 20 grams. The wireless pushbutton tracker FTTB 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 w position. The sensor then sends a presence telegram every 60 seconds. An internal 3 V button cell CR2032 supplies power for several years.