AKRACING Office Series Onyx Computer Chair – Top Grain Leather Seat – PU Leather Back – Black Steel, Metal Frame – 5-star Base – Black – Armrest 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. Features 4D armrests adjustable in four directions: up & down, back & forth, in & out, and rotate to the sides. Adjustable height, 180 degrees backrest recline, and rocking function with adjustable tension and tilt lock. Integrated steel frame and one-piece steel pipe structure undergo an 11-process quality control inspection to guarantee proper load-bearing performance. Cold-cured foam offers ultimate durability and comfort, and is guaranteed to retain its shape for many years. All backed by our industry leading warranty: 5 years on the chair and 10 years on the frame