The 4 mm (027 815) and 6 mm (027 816) shaft diameters allow for accurate readings in sample volumes as small as 150 µl and 200 µl respectively. The 4 mm probe has a 120 mm reach and the 6 mm probe has a 180 mm reach, making them ideal for use in test tubes and small vessels. Both probes are made from glass and have a 7 pin DIN connector so they can be used with any of Jenway's bench conductivity meters. Please view the datasheets for more information.