So what did I learn to day .
That Redcat Racing's part's Number BS701-019 is miss labeled . There website states : Pinion Gear 23T (.6 Mod), M3 Screw ~ . This is partially in correct it is a 23 tooth pinion but it not mod .6 / metric 48 pitch it is in fact imperial 48 pitch go figure . So don't waste your money if your looking to gear your Ground Pounder down on .6 modual pinions as you will burn through a spur in no time.
P.S. if your new to the hobby the best deals on 48 pitch pinion gears is the Robinson Racing Six pack starter set Part # 1050 / 1055 .
Part #1050 comes with a 16T 18T 20T 22T 24T 26T steel pinions Part # 1055 comes with 15T 17T 19T 21T 23T 25T steel pinion . There a heck of a deal at as each set normally sels for less than $16.00 .