Danfoss RA/VL thermostatic radiator sensor, OEM order code 013G2951 — a self-acting thermostatic operator (sensor head): the gas-charged sensing element expands and contracts with room temperature and drives the valve cone through the head, throttling flow to hold the set room temperature with no external power. It clamps onto Danfoss RAVL radiator valves via the RAVL connection (clamp ring fixing) and requires no wiring or batteries. Temperature setting range 5 °C to 26 °C; sensing charge gas; housing colour White RAL 9016. The head provides built-in frost protection (holds a minimum ~8 °C when turned to the snowflake position), adjustable maximum/minimum temperature limitation and set-point locking with hidden pins under the dial. Supplied as a service set — sensor, gland seal — to refurbish an installed RAVL valve; includes RA/VL sensor 013G2950 and gland seal 013U0070. Genuine Danfoss part; technical data quoted verbatim from store.danfoss.com (code 013G2951). OEM P/N 013G2951, EAN 5702420077833. HS 9032.10 (thermostats). Modulates refrigerant flow to the evaporator in response to superheat at the evaporator outlet.