Alera ALESR42LS50B Strada Series Mid-Back Swivel/Tilt Chair w/Brown Top-Grain Leather Tailored seat and back with top-grain leather upholstery. Waterfall seat reduces pressure at the back of knees. Roll armrests with padded leather caps for added comfort. Heavy-duty nylon base has dual-wheel casters for easy mobility. (alternative casters are available) Casters supplied with this chair are not suitable for all floor types.