I bought this to use on a project, but I've changed my approach to the project - there have been some discussions on this NG about such items, so here is one with a cheap 99 cent starting price. Here is the link:
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so you don't have to follow the link to see what it is, it's a microprocessor based process control switch - it uses prox sensor (or some other types) inputs and actuates a relay based on speed setpoints you enter. It is in a NEMA enclosure. Typically used for overspeed or underspeed protection, slipping belt detection, and variouis machine control applications.
I bought it surplus, but it sure looks like it's new. Dated 3-28-01