ER series collets, first produced by Rego-Fix but now available from a wide range of manufacturers, are highly versatile collets that offer a large clamping range and great accuracy. They can be used to hold tools and in some instances can be used to hold small workpieces, too. The number in the name designates the size (and thereby clamping range). An ER32 collet has a diameter of 33mm and a clamping range between 1mm and 21mm. These collets can be used to hold any tool within that clamping range.