12" x 24" x .040 POLYCARBONATE CLEAR PLASTIC SHEET LEXAN The linear dimensions of our sheets are nominal and they have a tolerance of +-1/8" in each direction (length and width) Excellent Light Transmission High/Low Temperature Resistance Thermoformable Brand Names for Polycarbonate: Lexan, Perspex, Makrolon, Tuffak, Speatech, Acrylate.