Very lightweight but did the job.  Because I lay a 5x7 rug on top, it is heavy enough not to slide, but I can still lift the corners and drag the rug to straighten it out.  Not sure if it would work well as an underpad for a runner rug.  I bought two 5x7 rug pads and one 2x9.  There were delivered without any packaging and were just left on my porch.  One bag was ripped slightly and the pad got a bit dirty.  It couldn't be wiped clean, but since it's a rug pad, I am not too concerned.