Blue Wave Gold 15-Year 21-ft Round Above Ground Pool Winter Cover Pool size: 21 feet Cover size: 25 feet Protects against sun, snow, ice and wind 4 foot overlap to ensure there is no stretching or ripping Pool size: 21 feet round Cover size: 25 feet round Protects against sun, snow, ice and wind 4-feet overlap to fit most top rails Heavy duty cable and winch tightener included