JohnDow Industries Replacement Fluid Extractor Tubes for use with JDI-172EV & JDI-277EV. 3 REPLACMENT TUBES - These Replacement Tubes are for Use with JohnDow Fluid Extractors. TUBE 1- Large Black Fitting - Hose Diameter 10mm - Is The Probe That connects to the Extractor. TUBE 2 - Smaller Black Fitting - Hose Diameter 6mm - DipStick Tube Used to Extracting. TUBE 3 - Small Red Fitting - Hose Diameter 7mm - DipStick Tube Used to Extracting