PAL versions of the single-disc volume sets started being released on February 19, 2007;.[1] As with the original Region 1 NTSC DVDs, each set contains four episodes per disc.[5][2][3][4][5] The Complete Book One Collection was released on January 26, 2009 containing all twenty episodes on five discs.[26] These Region 2 releases lack the commentary tracks and other DVD extras found on the Region 1 releases.