Derby Duck Racer Toy for your pool/spas/hot tubs/swim spas part #7344 Derby Duck - For Your Spa Or Pool - Size: 3.5" x 3.5" x 3.5" The Derby Duck is responsible for the recent groundswell of charity. Charity Duck Derby can bring over 30,000 rubber ducks to a race where one lucky duck purchaser would win the prize. Size: 3.5" X 3.5" X 3.5" Also fun for kids and adults alike.