The specific gravity 60/60°F scale compares the relative density of a given liquid with that of water, at 60°F (15.6°C). The instruments listed are similar to hydrometers included in ISO 650 and in the (now superseded) 1960 issue of BS 718.
General Purpose Specific Gravity Hydrometers Series S50
Range Span of 0.050°SG
Length = 190mm
Divided in 0.002°SG