One side of each piece has little knobs finished to create holding surface other side is flat. We used one for a TV table. Each tred of the 24 are 11.25 x 41.25 x 1.375 thick There is also one landing which is 41.25 x 60 wide If you could use this as a staircase the complete set w engineering certificate was around 24,000 4 years ago. It was rejected by the client after the contractor had signed for it but not noticed that the glass has a green rather than blue colour like the rest of the penthouse they had worked on. I bought it for considerably less and so can you. Stored in Shawnigan, sample in Victoria. Open to reasonable offer or will part out or build tables.