Found this in north Texas several years ago. If it wasn't flattened it would be approximately 3.5" tall and 2.25" wide, has no visible markings, appears to be aluminum. The top contains threads on the inside.
A friend with better eyesight than me was able to find some markings deep inside the base that read... Kenilworth 21 Sterling
I think it is part of a salt/pepper set as Alchemy stated.