0.4mm (0.016") thickness: 305mm x 305mm (12" x 12") This is a sheet of carbon fibre (or carbon fiber if you prefer)... Manufactured here at our works by laminating and compressing two layers of 200g woven carbon fiber (fibre) fabric under a vacuum and curing the product at 120 Deg C, which produces a 0.4mm (0.016") thickness (16 thousandths of an inch)