These are the 5106A 15 x 24 x 5mm Ball Bearingsfor the Traxxas X-Maxx Monster Truck.
Steel construction with black rubber seals
Used as the outer bearing in the front steering blocks and the rear stub axle carriers
Two 15 x 24 x 5mm Black Rubber Sealed Ball Bearings
Inner Diameter: 15mm
Outer Diameter: 24mm