Cliff Keen Ultra Mesh Basketball Referee Shirt. The choice of premier, championship-caliber basketball officials worldwide. EZ-Care ULTRA-Mesh® fabric gives you the shape, coolness and professional fit and taper in one garment! Signature stripes approved for NFHS contests in vibrant black and optic white pattern. Fortified with Cliff Keen’s MXS® fabric Technology, wicking moisture from the body to provide you with a performance edge.