Olson Saw CB50030BL Shopsmith Band Saw Accessory Cool Blocks For Shop smith Band Saws Contains: 2 guide blocks 3/8" x 3/8" x 1" and 2 guide blocks 3/8" x 1/4" x 112" Cool Blocks blade guides are made from a high tech, non-metallic composite material, "Graphite Impregnated Phenolic Laminate"