Integral sensing head for use with individual valve bodies Drayton TRV4 Classic Thermostatic Radiator Valve Integral Head in White/Chrome Plastic. Drayton's UK's best selling range of thermostatic radiator valves sets the standards for design, performance and quality, including Thermostatic Radiator Valve 4 lock shield and push-fit packs to suit most domestic and commercial heating systems. Drayton TRV4 Head Only Chrome & White Finish. Rated 'A' for efficiency., Manufacturer: Drayton Heating Controls