Rotary hammers with key chuck
prices on 2 models
Key
— a chuck designed to install a tool with a cylindrical shank (most often drills) and use when drilling; poorly suited for chiselling, usually supplied in addition to SDS. Thus, it is similar to a quick-clamping one, but differs from it in the need for a key to install / remove a working tool. This somewhat increases the reliability, but the replacement of the tool takes quite a long time and becomes impossible if the key is lost.