Connect Thermostats are electronic radiator thermostats and are used in combination with Danfoss Link™ Central Controller. Compatibility Runs on two AA alkaline batteries. Fits standard radiator valves RA, RAV, RAVL, RTD (Danfoss), M30 (TA, Heimeier, Honeywell, Oventrop) and M28 (MMA, Herz, Orkli, Comap). Key features: • Frost protection • ‘Valve exercise’ function • PID control • Battery lifetime up to two years • Warnings: ‘low battery’ and ‘no signal’ • Variable setback in steps of 0.5°C • Max./min. limitation • Child lock • ‘Open-window’ detection • Backlit display.