This is awesome!  It gets cold and I always turn off my heat at night so I needed this to keep us cozy and warm while sleeping.  I really love it and the best part?  I own a Sleep Number bed that has a movable base (foot and head go up and down).  It is deep enough that it stays around the mattress even when both ends are lifted!!  This isn't always the case with sheets and mattress pads, but I highly recommend this as it does everything I need!