Onyx is the true king of the AKRacing Office Series and aesthetically, is about as sophisticated as it gets. Available in PU leather and top grain leather (Onyx Deluxe) upholstery, it offers the executive look and feel, as well as extended features. A wide frame, flat seat, 4D arm rests, Rock It and Lock It function, advanced high tensile strength molded aluminum base, exclusive stitching and 100% more foam than AKRacing essentials chairs – all of that functionality is meant to make Onyx comfy and accommodating to give you the best fit possible.- Pleather cover on front and back (Onyx) / Top grain leather on front / pleather on back (Onyx Deluxe)- All-metal frame with 100% more cold-cured foam for maximum comfort and durability- Flat seat- Advanced mechanism with Rock It & Lock It function- Pillow set included- 4D adjustable armrests- 2.6 inch casters- Class 4 gas lift