The left and right side wheels are slightly different. The correct wheel will have the arrow shapes on the tire tread pointed towards the REAR of the stroller. Be CERTAIN that the wheels are placed on the correct side of the axle, because this is intended to be a Commercial Bounce House one-time assembly. • Locate an axle lock. While holding the axle from the opposite side, orient the axle lock with the larger side closest to the wheel and snap it onto the axle. See Figure 4.