Check the listing for details. Intex PureSpa water flow sensor paddle. Condition: New. Listed at 12.99 USD. This is a replacement flow sensor paddle for the Intex PureSpa family of inflatable hot tubs, but may work on other models as well. This does not include the sensor which is the black tube with the wires and connector. If your pump/heater unit is displaying an E90 error and you find that your magnet is rusty due to the plastic cracking or other things like the one to the left, you should replace it with a new one as it could be one possible cause of your E90 error. The fully assembled flow sensors are selling for between $35 and $50. Why spend all that money when you can repair this yourself. The part you are buying is a 3D printed version made from ABS plastic with the magnet completely sealed to prevent it from being exposed to the water and rusting yet again. NOTE: Please check and make sure that this is the part that you need prior to ordering. There are many causes of the E90 error and this is only one of them.