This item functions beautifully, and there is nothing any better for less money. No association with the maker, just a happy with the product.
You may download a free speed check disc as a PDF file. Open and print it on heavy paper and a small fluorescent test lamp will serve as the 60 HZ light source. If your speed is correct, the lines appear to stand still.
I agree with Jim, the KAB is worth every penny of the $100.00 asking price. I've had mine for several years and it is a valuable tool.
However, if bucks are in short supply, here's a cost effective solution.