21# High Sensitivity Premium Thermal Paper Bright White Smooth SurfaceFade Resistant Smear Resistant4-1/8" x 330’ RollsThis roll is Perforated every 8-1/2 Inches With Black Sensing Mark on Back Printed with Duty to Warn Information on Back1-1/2" Cardboard Core4-3/8" Outside Diameter8 Rolls Pe1-3/4" Cardboard Corer Carton