A tool unit for a handheld power tool having an oscillating output unit, having a fastening means for attachment to the output unit, and having a working edge that transitions into a lateral boundary line. In a gain control method for the variable gain amplifier circuit, a bias voltage applied to the input section of the emitter-grounded amplifier circuit is kept constant, and the output impedance of the emitter follower is changed in a direction in which the gain of the emitter-grounded amplifier circuit decreases. Another kit includes: a sterile fluid; a syringe for injecting the fluid into a bone; a curing agent adapted to cure the fluid to polymerize andor cross-link; and a container adapted to maintain the sterility of contents of the container. The role is associated with the request, the principal, and the resource.