This plastic cover measures 16 3/4" x 12 1/2" x 1 1/2" and shows some common age yellowing & tanning. I think this is from around the 1960's. A rare, vintage piece to find. It says-

enjoy
frosty, refreshing,
sugar free
FRESCA

Fresca was manufactured by the Coca-Cola Co.

There are scratches from use, storage and handling. There's about a 3-inch hairline crack near the top, opposite of 'enjoy'. There's a small place on the top. And at the bottom on the side a small piece that has broken off. It can be displayed where it's not as noticeable. There are scuffs, wear, light discolorations, etc. 

It may have been a vending machine insert, lighted sign topper, or for a soda fountain / menu board.

Perhaps it was used in places such as Woolworth's luncheonette restaurants- the piece is circa 1960's I think.

Pictures taken of all sides/angles, including top, bottom and close-up. Thanks for your interest and looking. Different shipping options available.