COATS&CLARK-Susan Bates Silvalume Crochet Hooks. These hooks have the broadest size range within the Susan Bates family of hooks. Made of lightweight aluminum; each Silvalume hook undergoes a special anodizing process; which etches away all surface impurities. In addition; each hook is heat treated for strength and durability and polished for a velvety smooth finish. Each size is color coded so you can find the size you need at a glance. These 40in circular hooks have a flexible cable with a hook on each end; which aids in working special stitch techniques with a large number of stitches. Imported.