One is ~57mm / 2.2" from top of fence to bottom of stop, so ~¼" / 5 mm from the table of my table saw (evolution tb255) fence. 

The other is ~81mm / 3.19", and about 5mm from the base of my cross cut sled back fence (around 3.25" high). DIY cross cut sled.

¼" SAE bolts fit through slots fine. 

I didn't like any of the other stop blocks I found, so I made my own simple one. It's designed to clamp down into a t track along the top of my cross cut fence and my table saw fence. Loosen two bolts at the top and you can remove it or flip it around to the back side to keep it out of the way. Made in tinker cad in a few minutes.