Ultrasonic transit time Sensor Clamp-On, Universal Size C3, paired, dedicated, Ex Zone 0,1,2, Class 1, Div 1,2, any pipe materials, Liquid, Pipe Diameter range 51 - 305 mm (2 - 12 in), Temperature -40C - +121C (-40F - +250F) Housing Polyetherimide/StSt corrosion resistant, incl. Couplant 7ME39600UC20 and sanding block for FST020, FST030 (FUS1010)