 Sets are formed as two-, eight-, and ten-car units, consisting of aluminium wide-bodied (2,930 mm) 20 m long four-door cars with no end gangway doors.Six-car sets were also scheduled to be built by fiscal 2011, but none was ultimately delivered., the fleet consists of six ten-car sets, 17 eight-car sets, and six two-car sets, based at Kotesashi, Minami-Iriso, Musashigaoka, and Tamagawa-Josui depots for use on Seibu Shinjuku Line and Seibu Ikebukuro Line workings.