The Janome AcuFeed 1/4 Inch Quilt Piecing Foot (Twin) is used with the AcuFeedsystem engaged on your Janome sewing machine. The Janome AcuFeed 1/4 Inch Quilt Piecing Foot (Twin) is an interchangeable foot for the Acufeed Flex twin holder. This Janome AcuFeed 1/4" Quilt Piecing Foot (Twin) has a built in flange to keep your seams at the 1/4" all the way around.