To fit some rock crawlers with a 12mm hex. High grip/traction wheel and soft tyre with high impact hardened black and blue outer rim plastic structure to ensure a long lasting wheel. These wheels are larger than most. To check these wheels will fit your model please check measurements below: 129mm External Diameter - 43mm Internal Diameter - 52mm Width - 12mm hex hub - 7mm edge of wheel to edge of hex hub.