Factory Team M4 low-profile wheel nuts
The Factory Team M4 low-profile wheel nuts from Associated Electrics are designed to fit on the front of 1/10th scale buggies such as the Team Associated B74, B64, TLR 22, TLR 22-4, Tekno EB410, Yokomo YZ-4 SF that require a thin nut to maintain the legal width limit at major events. With large-diameter locking serrations, these wheel nuts bite into the face of the wheel to create a secure hold and they come in sets of four.
Source: Associated Electrics [associatedelectrics.com]