Apparatus and methods for classifying web sites are provided. The symbol mapper operates to generate a sequence of symbols from a binary-source data stream containing a message to be transmitted, and the pulse-shaping filter generates a baseband signal based on the sequence of symbols. The flow grating partially obstructs the cross-sectional area of the channel, and is provided with passages. A distance calculator calculates a distance from the antenna to the tag using the phase difference and a wavelength of the intermediate frequency signal. The pair of hydraulic cylinders is actuated by the tractor hydraulic system wherein each of the hydraulic cylinders extends between one of the removable brackets and one of the rocker arms in order to move the limb shield between a retracted position to an angled protection position.