deb http://deb.debian.org/debian testing main contrib non-free-firmware non-free
deb http://security.debian.org/debian-security testing-security main contrib non-free-firmware non-free

# testing-updates, previously known as 'volatile'
deb http://deb.debian.org/debian testing-updates main contrib non-free-firmware non-free

# testing-backports, previously on backports.debian.org
deb http://deb.debian.org/debian testing-backports main contrib non-free-firmware non-free