Abstract: A filament retaining device is disclosed for a chimney and duct cleaning tool. The device comprises a socket having a bore defined by a side wall of the socket and a plurality of pairs of apertures disposed in the side wall of the socket, the pairs of apertures being separated longitudinally of the socket. The device further comprises a plug arranged to move in sliding relation within the bore of the socket. The plug comprises a plurality of channels disposed therein, separated longitudinally of the plug, and separately alignable with a pair of apertures in the side wall. The device further comprises an adjustment member for adjusting a position of the plug within the bore.