Eurotronic Stella Pro EnOcean (A5-20-01) Energy-Saving Controller
EUROtronic Stella Pro EnOcean radiator actuator, EU 868 MHz, EEP A5-20-01. Uses a 3.6 V lithium C-cell and M30 × 1.5 mm valve connection. Requires an EnOcean controller; not a Z-Wave device.