Good working 5C collets. As with many other machine products from China, you need to remove the grinding dust and, most importantly, deburr and chamfer the edges with a file. They are very sharp and will cut your fingers! 90 degree surfaces are flat enough and accurate enough for most jobs. Collets are well clamped and hold the workpiece securely. Very good repeatability. The collet stop also works well with this item. Once configured, it saves time. Feel free to buy if you need it.