KPM Aqua-Boy GEMI [GEMI-KIT] Cereals Moisture Meter w/ All Electrodes. The Aqua-Boy GEM moisture meter is specifically calibrated and tailor made for the grain, cereal and agricultural industry. Aqua-Boy moisture meters analyse the moisture content of solid materials in a host of applications. Easy to use and highly portable, these compact meters deliver instant results with an accuracy of 0.1%. Recommended by official test and research laboratories, Aqua-Boy moisture meters are the automatic choice of industrial specialists and scientists worldwide.