Alvantor Ergonomic Office Chair with Lumbar Support, Flip-Up Armrests & Mesh Back, Black

【Space-Saving 90° Flip-Up Armrests】 Adjustable padded armrests provide ergonomic shoulder support and flip vertically to slide under desks, perfect for compact spaces. The 3D armrest design reduces strain during prolonged typing or gaming sessions, accommodating users of all heights (tested for 95% percentile comfort). 【Breathable Ergonomic Backrest】 Curved high-elastic mesh back conforms to spinal contours with dynamic lumbar support, reducing lower back pain. The ultra-breathable polyester mesh enhances airflow—up to 40% cooler than traditional upholstery—while the 105°-120° tilt lock lets you recline securely. 【Pressure-Relieving Seat Cushion】 4.7" thick high-resilience foam seat exceeds industry density standards (55kg/m³) to prevent sagging. The waterfall edge design improves leg circulation, and the anti-slip textured fabric reduces heat buildup by 30% compared to leather chairs. 【Commercial-Grade Stability】 Reinforced SGS-certified Class-4 gas cylinder (100,000 cycles) and 1.8mm thickened steel frame ensure safety. Nylon dual-wheel casters (2.5” diameter) roll quietly on hardwood/tile, and the 23.6" widened base prevents tipping (tested at 950kg static load). 【Quick No-Tools Assembly】 Pre-installed components and color-coded instructions enable 1-person setup in under 15 minutes. Includes all hardware (pre-greased screws, wrench) and a 10-year warranty on the metal frame + 2-year coverage for mechanical parts.