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 that etches away all surface impurities. In addition, each hook is heat treated for strength and durability and polished for a velvety smooth finish. This hook has a 55cm (22in) flexible cable, which aids in working a large number of stitches. Comes in a variety of colours. The colour is chosen at random and cannot be selected.