Kensington 56146 Solemate Plus Adjustable Footrest, Gray
I had considered buying one of the cheaper foot rests made of just plastic, but worried that they would too flimsy. I'm glad I purchased the Kensington. The rubber and adjustable height are features I think are fundamental to the product. The footrest does not slip (nor smell), and is barely noticeable to me while I work during the day. Which is how I think it should work (behind the scenes).