4x16 CombinationType E Porcelain Markerboard / Natural Cork. Combination Magnetic Markerboard / Natural Cork. Premium Combination Boards - A versatile communication tool that puts class in the classroom. our premium combination boards are shipped fully assembled and are configured to meet the highest level of product specifications. Aluminum framed X-CEL units blend the function of a chalkboard or markerboard with a tackboard and feature a full-length chalkrail joiner strips and a 1 maprail above the top of the writing surface. FREE SHIPPING! FREE SHIPPING!