This drill chuck has unique locking function, traditional locking methods, back having ratchet teeth, the locking pieces mounted on the rear sleeve, more effective in preventing work loose off, so that the clamp chuck,more reliably support tools. Instantly convert impact driver to hold non-quick change drill driver bits. Easily locks onto and releases drill bits. Feature - Color: As shown - Material: metal+plastic - Size: 7.5 x 4 x 4cm - Easily locks onto and releases drill bits. Instantly convert impact driver to hold non-quick change drill driver bits. . - Made of material for long lasting use. - Easy to install and operate. - Unique locking function, traditional locking methods, back having ratchet teeth, the locking pieces mounted on the rear sleeve, more effective in preventing work loose off, so that the clamp chuck,more reliably support tools. - and high quality, durable in use.