Abstract: An active tensioning device for a looped cord of a window covering system. The active tensioning device comprises a body having a channel configured to receive a section of the looped cord therein. The channel has a first wall allowing the section of the looped cord to slide thereon and a second wall having at least one cord engaging member engageable with the section of the looped cord. The active tensioning device is pivotable about the looped cord between an inoperative configuration where the looped cord contacts the second wall of the channel and an operative configuration where the looped cord contacts the first wall of the channel. The active tensioning device is balanced to be urged towards the inoperative configuration by gravity.