Houston residents may want to pay close attention to their loose change after coin collectors put five pennies worth $200 apiece in local circulation to promote a coin show.

Carl Schwenker, a volunteer at the Greater Houston Coin Club, which distributed the pennies, told ABC News that the coins were first put into circulation Wednesday, and could be redeemed at the 57th Money Show of the Southwest for $200.

"If you see one of these pennies, bring that sucker down to the coin show," he said.

The coins are valued so highly because of their age and the circumstances surrounding their minting, said Schwenker.

The pennies were part of a select few minted in Denver in 1914, and as others from the lot have been lost through the years, the remaining ones have increased in value, said Schwenker.

While the coin club hopes Houston residents will recognize the coins when they find them, Schwenker said it's not likely.

"There's a very high probability they will be lost in the system. I went to a cashier … I actually put it right in her hand, and she did not notice it," he said.

But here's a few clues for identifying the coins: The pennies have an unusual backside that reads "one cent," they're dated 1914 and bear the capital letter "D" under the year.

The show, at the George R. Brown Convention Center, ends Dec. 7.