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 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 22 colors available. Please specify your preferred color numbers after purchase. The quantity of each color can be mixed.