SenDec 160585 Magnetic Surface-Mount Tachometer, Model No. SFT806-0222

The unit works as advertised. The lead wire is about 4 feet long which is important in some applications. Since the unit has an LED display it does not work well when the temperature is below about 40 degrees. I would consider it for indoor applications only.

The display is small but adequate. Simple screw holes are provided for mounting. It comes with a tiny magnet in an envelope. You're supposed to glue the magnet to the shaft of what you are metering. No glue is provided. The sending unit is a tiny threaded shaft with two fragile nuts that must be mounted within a 1/4 inch of the magnet. No mounting bracket is provided. Two fragile little wires connect the pickup shaft to the display. No disconnect is provided. Both pieces are always connected. That means you must thread the tiny shaft and its wire from the display mount to the shaft . . . or just leave the display dangling until you get everything setup. Forget taking your test rig apart. You will beat up the display or drag it across the floor and step on it as I did. Once assembled, you must tweek your fabricated mount to get the shaft closer than 1/4 inch from the shaft/magnet. No matter how close, the display will read erroneously. Sounds like I just got a bad one, doesn't it. No such luck. I bought two and both of them are pieces of trash. They're both going back to Northern . . . if Northern will accept them in theri beatup condition.