https://www.etrailer.com/Balls/Equal-i-zer/EQ91-00-6140.html
Today we’re going to be taking a look at the 2-5/16″ Hitch Ball for Equalizer Weight Distribution Systems. The trailer hitch ball is designed for use with Equalizer Weight Distribution Systems. Equalizer hitch ball products exceed SAE J684 testing and certification. The unit’s made from a very sturdy steel construction, and it’s going to feature a durable, rust-resistant, double-chrome plating. The lock washer and the nut are included. Right here on the platform, you can see that it has two sides that are flat.
Note: Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
https://www.banggood.com/6pcs-HSS-14-Inch-Hex-Shank-M3-M10-Combination-Drill-Tap-Bit-Set-Metric-Deburr-Countersink-Bits-p-1023662.html