TG1=GL1 (Certified, not stamped) Sheet size 635mm x 635mm Due to the way our website calculates shipping, for multiple quantities it may over charge. If this happens, we will automatically refund the difference. Skycraft reserve the right to change the selected courier and charge the difference where geographical needs apply. If you are unsure about shipping charges or any of the above, please email us info@skycraft.ltd for an accurate shipping quote.