Yiguo 4pcs Aluminum Wheel Hex Mount for RC 1/18 WLtoys A949 A959 A969 A979 K929 Upgrade Parts Blue Suitable for WL toys 1/18 A949 A959 A969 A979 K929 Aluminum alloy material, high protection and long durability The outer diameter is approx 7 mm Part No.: A580037