I actually got mine from banggood (On sale for <$9 with free shipping right now too) because I couldn’t find one on Amazon with Prime shipping:
But then sure enough soon as I mentioned to him djk4linux shared a link to one on Amazon:
It’s a bit more…but you can have it in a day or two instead of a week or two 😀
My DW660 actually clocks in at about 28,000 straight to the wall and I was surprised how far I had to turn down my speed controller to get it to 20k. Though my readings on there may not be super accurate as I just put a bit of the reflective tape that comes with the tach on one face of the collet nut and didn’t bother to put black tape on the other faces, so if it’s catching a reflection off them it would read artificially high. But since it read low right to the wall I figure it’s probably pretty close.
On my needle cutter the bell of the motor is chrome so I put black tape over most of it and just a little bit of reflective tape there.