Dosatron D14MZ5, auto PPM

Barely used, like new, back screw plate is slightly damaged, but works fine.
Originally $800, ASKING FOR $550
Installed directly in the water supply line, the DOSATRON operates
by using water pressure as the power source. The water activates the
DOSATRON, which takes up the required percentage of concentrate.
Inside the DOSATRON, the concentrate is mixed with the water. The
water pressure forces the solution downstream. The dose of concentrate
will be directly proportional to the volume of water entering the
DOSATRON, regardless of variations in flow or pressure which may occur
in the main line.
Product Info:
http://www.dosatronusa.com/products/product-catalogue/d14mz5-14-gpm.aspx