Mechanical engineering, design, flat-bed trailers, end-dump trailers, side-dump trailers, gooseneck trailers, 5th-wheel trailers, tanker trailers, haz-mat trailers, heavy-haul trailers, scissor lifts, aerial lifts, man lifts, bucket trucks, cherry pickers, trailer bumpers, trailer rear impact guards, trailer underride guards, trailer safety chains, weight-distributing trailer hitches, trailer tarping systems, exercise equipment, garbage trucks, refuse trucks, side loaders, core-drilling equipment, road construction equipment, manufacturing equipment, powered industrial truck attachments, forklift attachments, fall protection, horizontal lifelines, auger conveyors, screw conveyors, belt conveyors, heavy equipment, hydraulic equipment, hydraulic valves, hydraulic cylinders, thrill rides, chairs, folding chairs, shower chairs, seating, safety analysis, risk analysis, hazard analysis, slip and falls, ATV winches, and sidewalk maintenance.