A handheld pole sander for performing different surface machining treatments including sanding, polishing, grinding or rubbing a work surface, comprising: an elongate body having two ends; a sanding head attached via a pivot mechanism to a first end of the elongate body; an electric motor mounted on the sander; wherein the sanding head comprises: a hood comprising a plate and a peripheral wall formed on the underside of the plate around the edge of the plate; an output spindle which projects from the hood; and a brush ring, comprising a circular ring, mounted on the underside of the plate adjacent the edge of the plate inside of the peripheral wall; wherein the electric motor, when activated, rotatingly drives the output spindle around an axis; wherein the brush ring is attached to the plate via at least one leaf spring; wherein one end of the at least leaf spring attaches to a top side of the circular ring, the other end attaches to the plate; or at least one wave spring; wherein the at least one wave spring is a nested wave spring, a crest to crest wave spring, a single turn wave spring, an interlace wave spring or a combination of such wave springs; wherein at least one aperture is formed through the plate; characterized in that, when the brush ring is attached to the plate via the at least one leaf spring, the at least one leaf spring extends through the at least one aperture in order for the other end to attach to a top side of the plate; wherein, when the brush ring is attached to the plate via the at least one wave spring, at least part of the wave spring extends through the at least one aperture in order for that part to attach to a top side of the plate. an elongate body having two ends; a sanding head attached via a pivot mechanism to a first end of the elongate body; an electric motor mounted on the sander; wherein the sanding head comprises: a hood comprising a plate and a peripheral wall formed on the underside of the plate around the edge of the plate; an output spindle which projects from the hood; and a brush ring, comprising a circular ring, mounted on the underside of the plate adjacent the edge of the plate inside of the peripheral wall; a hood comprising a plate and a peripheral wall formed on the underside of the plate around the edge of the plate; an output spindle which projects from the hood; and a brush ring, comprising a circular ring, mounted on the underside of the plate adjacent the edge of the plate inside of the peripheral wall; wherein the electric motor, when activated, rotatingly drives the output spindle around an axis; wherein the brush ring is attached to the plate via at least one leaf spring; wherein one end of the at least leaf spring attaches to a top side of the circular ring, the other end attaches to the plate; or at least one wave spring; wherein the at least one wave spring is a nested wave spring, a crest to crest wave spring, a single turn wave spring, an interlace wave spring or a combination of such wave springs; wherein at least one aperture is formed through the plate; characterized in that, when the brush ring is attached to the plate via the at least one leaf spring, the at least one leaf spring extends through the at least one aperture in order for the other end to attach to a top side of the plate; wherein, when the brush ring is attached to the plate via the at least one wave spring, at least part of the wave spring extends through the at least one aperture in order for that part to attach to a top side of the plate.