This puffer contains 100% responsibly sourced goose down. Ready for you, winter. The Mega Puff is mega puffy and mega warm because it's mega filled with 100% responsibly sourced goose down. It’s made with CliMATTE — water-repellent Japanese ripstop fabric with a matte finish and a soft feel. This version is wind resistant. It's been recently redesigned for a better fit and range of movement.