Farm dairy legislation prohibits any non-complying thermometer even being in a registered dairy premise. No thermometers containing mercury or glass comply. Our Dairy Special thermometer has no mercury or glass. Its dial scale is very easy to read. It is pocket size and very reasonably priced. The pen-clip sheath doubles as an extension handle. Dial is 25mm diameter with red pointer. Scale -5 C to 115 C. Length 14cm o.a.