A slippery surface for ALL your sewing with a tacky back to hold it in place. The rectangular hole measures 1inx1.5in to allow the feed dogs to show through. This allows sewing with difficult fabrics such as leather and pleather, minkee, flannel and fleece. Also works with the walking foot for gliding large quilts while stitching-in-the-ditch, as well as free motion stitching. 12inx18in size.