flow meter

I have 3 unopened swiss flow meters for sale. Selling the lot for $150 with free shipping or individually for $60 each, free shipping. Heres the link to the product they cost $60 new + $20 shipping if bought direct from Swiss Flow. http://www.swissflow.com/sf800.html

So this is different than other inquiries that I found so I am hoping for some guidance / help in this realm. I have installed a flow meter prior to my water filter. As you will see with the pictures and links etc. I have wire the flow meter to the RPI based on the diagrams I have found. (...