Micro Metal is a thin metallic thread that can be used for thoraxes or as ribbing and bodies on flies ranging from dries to nymphs to salmon, streamer and saltwater patterns. Semperfli starts with a fine core and wraps it with soft metal tinsel in a broad range of colors. The thread is just 0.106mm (0.0036 inch) diameter, about the same as 3/0 (200 denier) thread. 75 meters (81.25 yards) per spool.