Ensure smooth, precise performance with the TKRBB15214 15x21x4 Ball Bearing (4), designed specifically for .4 CVA driveshafts. These high-quality bearings reduce friction, improve drivetrain efficiency, and enhance durability for demanding RC action. Compatible with a wide range of Tekno RC models—including ET48, EB48, and SCT410 series—these bearings are ideal for racers and hobbyists seeking reliable performance upgrades. Upgrade your Tekno RC vehicle with these essential bearings to maintain optimal power transfer, smoother acceleration, and longer-lasting drivetrain components.