The instrument (10) has a motor drive driving a tool e.g. drill bit and dash line. A lateral handle (32) is rotatably moved away from an elongated body (12) such that the handle is removably secured at the body. The handle is defined in different positions along a longitudinal axis of the body. The handle comprises a recess receiving the body. The handle comprises an adjustable finger whose tip is inserted at an inner surface of the recess and prestressed against the body for latching the handle at the body in a position.
