Certified Intrinsically safe, the Yellow Jacket is used to measure the thickness of floating or sinking hydrocarbons in groundwater accurately, safely and reliably. The easy-to-read heavy duty Kynar jacketed tape is accurate to 1/100 of a foot with printing beneath the jacketing to eliminate the possibility of the graduations wearing off. The Yellow Jacket has modular electronics and an easy-to-replace probe. The unit is powered by a single 9-volt battery and comes standard with a carrying case and cleaning kit.