08 ounce (4pcs) C Hubs 4.4 ounce (pair) Include:Brass Steering Knuckles (2 pcs)Brass C Hubs (2 pcs)Brass Hexes (4 pcs)Brass Portal Covers (2 pcs)Mounting Hardware (1 pack) Fits for Traxxas TRX-4M Bronco and Defender, TRX4MT 1/18 Scale Crawler. 4., 6 out of 5 stars Manufacturer FriHobby Add weight to the wheels to lower the center of gravity, ensuring better balance. About this item Suitable for Traxxas 1/18 TRX4M RC Crawler Car. Made of highest quality brass material, and with finest workmanship, which is rust proof, wear resistant and durable. Increase the weight to change the center of gravity for maintaining the balance of the car body. Machined for precision. Increased strength and precision Brass Steering Blocks Knuckle For 1/18 RC Crawler Traxxas TRX4m TRX4-M... Knuckles Brass RC Crawler Upgrade Parts Brass Caster Blocks For TRX4M 1/18 RC Crawlers - Black Gold C-Hubs For Bronco & Defender RC Caster Blocks With screws, bearings, and an L-shaped wrench included, the caster blocks and steering blocks combo for TRX4M upgrades are convenient to install Made of high-grade brass to prevent corrosion and enhance the appearance.