archboard features unique lock-o-matic dual arch rings and 1/8″ brown hardboard. Locking feature on rings prevents the mechanism from being opened accidentally. Surface has a smooth finish on the front and back. Archboard holds letter-size and a4-size papers and offers a 2-1/2″ capacity. larger quantity quotes available. Please call 1-888-978-7759. this product arrives to most customers in 2-3 business days.