A dedicated battery-powered assembly of devices intended to be used to remove circular sections of the skull vault (calvarium) to provide access to the interior for diagnosis (e.g., the insertion of a neuroscope), or treatments [e.g., to alleviate intracranial pressure (ICP)]; it may also be used for the removal of a bone flap for brain surgery. It typically consists of a handpiece containing a motor (engine), a battery-pack, an attachment with a clutch system that disengages the cutting tool when the inner table has been penetrated preventing injury to the brain, and an exchangeable rotating cutting tool (e.g., a cranial drill bit, bur, trephine or perforator). This is a single-use device.