DDIRC Pro 32P Hardened Steel Upgrade Pinion Gear Set: 13T 14T 15T 16T 17T fit 5mm RC Motor Shaft (Work with Steel Spur Gear) for RC Cars, Set of 5

I didn't read the size of the hole so they don't fit on my ARRMA vehicles cuz they ar to big but judging by looks they seem to be a good steel

Very high quality. I like that these use M3 set screws (2.0mm hex).

Put the 18t on my arrma Typhon 3s and it had a noticeable speed increase and no overheating with flat out bashing

They arived ahead of time and they were well made . I will buy more as needed

By far these are the best ones for the price and seem to hold up. No complaints here.

I liked the well done set screws. Well made. Good value.