re: Table saw sleds, How 5 cut do you need to be?

The ones I have gotten are Aluminum. I saw the discrepancy when I first ordered, and after thinking about it figured if the MicroJig product was plastic, any metal would be ok. I guess my word use of ball bearing was trying to eggsplain the adjustable effect that widens them in the slot. It's full travel, to the point you can actually lock them in place, or make them sloppy. I kinda prefer the just right option though. 

Yean, they really aren't stinky at all.... :-)

Both my General, and my contractor Delta have a standard 3/8 x 3/4 slot, but both are a sloppy 3/4" so the adjustable feature is a good thing.