Hydrotech RO Vessel Wrench for Hydrotech 1240 series systems.
If you are not sure which Hydrotech vessel wrench that your system uses, look on the back of the dust cover for a silver sticker. This sticker lists the model number of your unit. If your model number begins 1010; 1230; or HTF, your unit uses the older style 21401003 wrench. If your model number begins with 1240, then your unit uses the newer style 21401240 vessel wrench.