This is the 5526 Antenna Crimp Nut Antenna Nut Tool Jato from Traxxas.
Traxxas has grown to become the number-1 selling name in RTR nitro and
electric models for the last 4 years running. No one has done more than
Traxxas to advance the RTR category with innovative thinking and fun
designs that make it easy for anyone to get started in the great R/C
hobby. Traxxas, truly the fastest name in Radio Control.