Optical Tachometer

[Gr8ful]

I have one that works great. I have the old SW manual ones I used with the sawmill that have a couple different rubber tips. I had to use one to check the rpm of the '38 Taylorcraft at full speed. I went very slow & careful & when the digitals came to Harbor Freight years ago I bought one of the 1st. I think when some things are sold on ebay for 1/2 price they may be rejects the employees se or other companies sell knowing they're defective but it's going to the US so they don't care.