Wooden box with black metal instrument panel; four padded metal feet on bottom; leather handle attached to side with two nickel connectors; nickel lock on side of base and lid; lid connects to base via two coated metal hinges (new); lid opens up to show panel; top has a small black plastic knob with dial printed onto metal below, a small metal eyepiece, and a small metal switch; in center is a moveable dial covered by glass; along side dial is a power cord with two warning tags; at bottom are two medium sized plastic knobs, one on left has dial printed onto metal below; three binding posts with black plastic covers at very bottom; small piece of paper taped to side identifies owner.

The Sunderman Conductivity Bridge, often used in conjunction with a conductivity cell and a water bath, measures the electromagnetic conductivity of small quantities of biological fluids. It is specifically designed to determine a sample serum's total base and to estimate its serum sodium, which has important clinical implications. Tests can be made using only 0.5 ml of sample.