A classic 1950s remote reading dial thermometer by well known makers, Negretti & Zambra, London.  Reading from 30'F to 80'F over 3/4 of the dial it is particularly sensitive to minor temperature fluctuations. With careful unravelling of the sturdy metal tube the heavy sensor could be installed up to approximately 2.7meters away, even through a wall!. Ideal for monitoring temperatures from room to room, room to cellar, room to garage, workshop etc. Glass dial is 125mm diameter, 170mm overall diameter and 65mm deep.