They are sort of heavy and clunky but they have a large, stable footprint and go up pretty high. No so hot in the post apocalyptic department, but that's why they make matte black and OD green and flat tan.
From the company:
6000lb Capacity. Patented design combines jack stand and bottle jack in one unit. Safety bar locks unit at desired height. Wide steel base for stability under load. Height Range: 11” to 21”. Perfect for SUV’s, off-road vehicles, construction jobs, framing and floor joist work.