I had purchased a 4 x 4 white shag rug to lay in center of small sectional.  The rug seemed heavy enough not to shift at first. However, it eventually did start moving around on the hardwood floor, so I purchased two of the 2 x 4 size of this non-slip rug pad.  The pads hold the rug perfectly stationary.  It does not stick to the hardwood but magically holds the rug in place and is easily adjustable if you want to move the rug to a different location.