EC Dipstick (formerly Nutrawand) by Control Wizard Products.
New Name! New Label! Same Easy to Use Meter! Now with the 4 most popular scales: EC, CF, 500:1ppm, and 700:1ppm! No matter what meters you have used in the past, the EC Dipstick can read just like it. EC Dipstick by Control Wizard Products dissolved salts pen, measures conductivity in PPM, EC and CF.
No calibration required, auto on/off. Very Nice!