In the USA, all Season One DVDs were encoded using NTSC. Since this is not compatible in most countries outside North America, Nickelodeon released separate DVDs in regions where the video would be encoded using PAL instead. These releases began on 19 February 2007; each DVD was released months after the original release. As with the original DVDs, each set contained four episodes on one disc, with the exception would be The Complete Book One Collection Box Set, which contained all of the twenty episodes in the season on five discs.