Since I upgraded to a new VFD (That's another story!) I do not have the RPM easily available, the vfd is inside a cabinet, the cover has 4 screws. I was curious about the speed I was chasing threads. I want to be able to tell people in Raleigh at what speed I chase threads. Someone recommended this inexpensive tachometer from Amazon. I tried it today. At first, I almost threw it in the garbage can. It was giving me crazy readings. Then I realized the shop light was shining on the shiny surface where I had placed the reflector tape. I added some painters tape, then the reflector on top of that. Instantly better. I was surprised to find out I was chasing at around 500 rpm. A little too fast.