DiDi/iRC 7mm to 12mm Adapter Remote Control Parts Aluminum Wheel Hex Adapter Hub for 1:18th Wltoys A949 A959 A969 A979 K929 RC Hobby Car 4-Pack Item name:7mm To 12mm Adapter (Hexagon Mount Seat) Upgrade Part:100% Brand New and Easy to Install, Made of Aluminum, Durable to use Come in 1 Set (4 pack as Picture), Upgrade your 1:18th RC car' Wheel by 1:10th RC car' Wheel. Basic Size:Outer diameter :approx 12 mm,Thickness: 5 mm Diameter of the hole:4 mm Fit For Wltoys1:18th A949 A959 A969 A979 K929 A959-b A969-b A979-b K929-b