Full Back Comfort Up To The Lower Neck On Any Chair You Clinically Proven To Ease Pressure On The Lower Back With Its Unique Combination Convex/concave Design Offers Complete Spinal Support Relieves Back Pain By Realigning The Spine And Supports Correct Posture Engineered Shape Confirms To Natural Spinal Curvature Cover Features Ventilation Zones For Added Breathability Contoured Cushioning Provides Supportive Comfort 8-position Height Adjustable Slider Mechanism In The Base Allows Height Adjustment Of Up To 4 Inches Height Adjustable From 23.5 To 27.5 Width: 12.5 Retail Box Measures 12.8 L X 4 W X 23.5 H