Scale calibration weight

[coast range]

What brand specifically or where do I get a good F1 class 100g weight? The reviews for the one on Amazon looked bad. The YouTube I watched said to order the one on eBay.

So where do I get a good one to calibrate my fx120i?

 

[coast range]

I do have one that came with my Rcbs triple beam. But not sure if that is accurate

 

[nm.otter]

How accurate do you need to be? NIST traceable standards are available.