The Allen HDX600 is a hydraulicakkt powered riding trowel designed to provide the power and torque demanded for panning. This double four-ft. diameter rider comes in a compact package. The machine’s weight-tohorsepower ratio and advanced hydraulics compare favorable to competitive ride-ons The HDX600 is the first in the series of Allen Hydra-Drive Extreme (HDX) all-hydraulic riders. Allen Engineering Corp. 800-643-0095.