The Gann BL-series surface moisture meter is a high-quality and versatile instrument for structural moisture measurement. It allows surface measurements with penetration into the structure up to 50 mm depth. The device includes a hold function for storing measurement values, as well as minimum and maximum value displays. It also features memory for the last five measurements and an adjustable alarm threshold with an audible buzzer. Additional functions include automatic power-off and automatic zero-point calibration before measurement. The measurement scale ranges from 0–200 units and the device comes with Finnish user instructions and calibration marking. It includes material compensation options for moisture content in weight percent and volume percent (CM), as well as a trend display for both hard and soft wood types. The package includes a 9V battery and a padded plastic storage case.