ACP or Aluminium Composite Mirror effect sheet is a stiff, rigid aluminium skin mirror comprised of 2 outside skins of aluminium and an internal PE plastic core. One side mirror effect finish, one side coated 'silver' mirror backing finish. The sheet is 3mm in thickness and is 8' x 4' (1220x2440mm) which can be cut to size at no extra cost. Pls note: this is not glass mirror, it's an aluminium sheet with high reflection finish - a free sample is available to guage suitability before purchasing. Contact out office for more details.