This is a replacement flow sensor paddle for the Intex PureSpa family of inflatable hot tubs, but may work on other models as well. 
Description
This is a replacement magnetic Water flow sensor paddle for the water flow sensors used in the Intex PureSpa brands of inflatable hot tubs. 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 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. It may be worth it to check out this youtube video (click here) before purchasing .
Karen Jacobs (verified owner) –
I have a 2018 Intex hottub. This year after putting it up my water flow sensor broke. I thought no problem I will go to the Intex website and get a new one. Unfortunately Intex no longer offers that part or any other parts for that model hotub. After searching the internet for any aftermarket parts I came across this website. I was so excited to see that they could 3D print the replacement part I needed. I thought I would have to purchase a new hottub. I can not say enough good things about the company or the part I received. Payment was easy shipping was super fast and the part even arrived 4 days earlier then estimated, and at $12.99 it was a bargain. The part fits perfectly and my old unit is running like a champ!