Features 1、The collet is small in size, easy to carry and store, and has fine workmanship, good elasticity and high accuracy. 2、Made of high‑quality high speed steel, the spring collet has anti‑rust and anti‑corrosion properties and has a long service life. 3、All collet surfaces are accuracy ground for an accurate fit, they have excellent grip on the cutter shank. 4、With high accuracy and strong holding force, the clamping range is large, so you don’t have to worry about the tool handle loosening during use. 5、Used in various machining applications, including boring, milling, reaming, tapping and grinding, compact and easy to install. Specification Item Type: Spring Collet Material: High Speed Steel Model: ER20-13mm Collet Inner Diameter: Approx. 13mm / 5.1in Diameter: Approx. 21mm / 8.3in Total Length: Approx. 31.5mm / 12.4in For 1/2 extension rod Package List 2 x Spring Collet