We had the stairs refinished and as a result our dogs slid down every morning.  It was funny the first time, then we got worried.  These treads are perfect for them and us.  They just lay on top of the wood.  No scratching or scarring.  And the best part (according to the paperwork that came with them) they can be washed in the machine - which I'm going to find out today.  We've had them for about 2 months and our 2 black labs and family of 4 have finally made them dingy enough to wash (we got the gray ones).