These are rollers for making Japanese "Yaen" fishing lures, for DIY use. There are 6 pieces. They have been tested in actual fishing conditions several times. They roll very well. They are thicker than the rollers I have listed for sale before. The hole diameter is 1.2mm, and a stainless steel rod of that size will pass through. 1.0mm rods also work well. There are 23 colors available. Please specify your preferred color numbers after purchase. The quantities can be mixed.