Urinometer
A Urinometer is a simple piece of equipment for determining urine specific gravity.
A typical urinometer is composed of a float, a weight, and a stem. The float is an air-filled glass tube, ending in the weight on the left and the stem on the right. The weight is a bulb filled with ball bearings embedded in a red solid, probably a glue of some sort. The glass stem extends to the right, and has calibrated graduations and numbers marked off to indicate specific gravity measurements.