Allis-Chalmers equipment  stainless steelplates1/32" thick-Could also be aluminum but seems to be denser like stainless--no way for me to tell-so it is what it is -Vintage signage-advertisement collectible-10-1/2" by 2" rectangular-most likely used on large equipment for name identification.--Quality item--lot of 3--Very rare to find these old plates