Thirteen treads, each 8 x 18 inches. Brown rug on top, black & slightly rubbery on the bottom. Bottoms are *not* non-slip, if you don't fasten them they'll slide around. I think they are made to be glued or nailed down.
Let me know when you'd like to pick up and I'll leave them on my front porch and email the address (between Davis & Teele).