It's a "cash for clunkers" program, but it has nothing to do with cars.

Instead, Gainesville Regional Utilities customers can trade in their old window air conditioning units for new ones for only $20.

Spend a little to save a lot, that's what GRU representatives are saying about Saturday's annual event that is now in its third year. Lowe's Manager Charlie Raulerson says the A.C. units are originally priced at about $260.

At the price of $20, that is almost 90-percent off. GRU pays most of the difference, which could end up costing the utility company thousands of dollars.

Only the first 100 GRU customers to each location in Gainesville will get a discounted A.C. unit.

"It's recommended to get here early because if tomorrow is like the past they are going to go very quickly," Raulerson says.

To be eligible for the trade-in, each person must bring a form of identification, a GRU bill dated no earlier than May, and an old A.C unit that is still in working condition.