【5-Year Warranty + Lifetime Support】At ProtoArc, we’re a brand you can trust. All of our ergonomic office chairs are built for long-term comfort and reliability. Each office chair comes with a 5-year warranty, including free replacement parts during the warranty period. Even after that, our expert team provides lifetime after-sales support—offering fast and dependable help whenever you need it. 【Professionally Certified & Trusted】All ProtoArc chairs meet the BS EN 1335 ergonomic standards and have been rigorously tested by SGS according to ANSI/BIFMA X5.1 for strength and stability. Equipped with a TÜV Rheinland–certified Class 4 gas lift (EN 16955), they ensure smooth and reliable height adjustment for both daily use and long-term performance. Trusted by remote workers, tech teams, and enterprise buyers for their quality, safety, and comfort. 【Customizable Seat Depth】Our ergonomic chair features 5-level seat depth adjustment (33–43cm), ideal for users approximately 163–190cm tall. Slide the seat forward or backward to match your leg length—perfect for relieving knee pressure and enhancing thigh support. A great choice for taller users, coders, gamers, or anyone seeking a comfortable desk chair for home or office use. 【Better Support Seat Cushion】55D High-Resilience Foam + 3-Layer Cushion Structure – Unlike ordinary foam that flattens over time, our seat features a patented 3-layer design: breathable mesh top, high-density 55D foam core, and reinforced base. This computer chair is tested to maintain shape after 3+ years of daily 8-hour use 【2-Way Adjustable Lumbar Support】With 6cm vertical and 2cm depth adjustment, the lumbar support can be moved to precisely match your lower back curve. The breathable, high-strength mesh keeps you cool and supported, making this ergonomic office chair ideal for long workdays at home or in the office. 【4-Position Recline】Find your perfect angle for any activity with four lockable positions: 90° for work, 105° for reading, 120° for calls, and 130° for relaxation. Adjust the recline tension effortlessly using the built-in knob for personalized comfort. 【3D Adjustable Headrest & Armrests】The large mesh headrest supports 3D adjustment—height, depth, and dual-axis rotation—to fit your head and neck naturally. Whether you’re sitting upright or leaning back, your neck stays aligned. The widened armrests adjust up to 7cm to match different seating styles, enhancing comfort across all desk chairs for work or home. 【Effortless Assembly】Our ergonomic chair comes with detailed installation videos, all required parts, and handy tools, making setup quick and hassle-free. You can have your new chair ready in just about 20 minutes and start enjoying a comfortable seating experience right away.