Vintage metal, silver-plate, I believe,  butter dish.  Nice ornate design with swirls and scallops on the tray/dish edge and a decorative finial knob on the lid.   This is used and vintage.  It shows signs of age and wear, mostly the patina.  I believe a good polishing would brighten it up.   This does not come with the glass insert, just the metal top and bottom.   Please view pictures for details.  MCM vintage silver-plate? butter dish, top and bottom.   

THANKS FOR LOOKING.  :)