O2 (UK) Telefónica O2 had a long-standing relationship with Arsenal F.C., being their shirt sponsor until the end of the 2005/2006 season. In 2005, a three-year deal was signed that saw Telefónica O2 become the team's exclusive mobile communications partner. O2 were the main sponsor of the Channel 4 reality TV show "Big Brother" from its second series (as BT Cellnet) in 2001 until its fourth series in 2003. They also sponsored the spin-off shows "Celebrity Big Brother 2" in 2002 and "" in 2003. In total O2 sponsored five series of the show. O2 sponsored music festivals, the Wireless Festivals, from
LSWR O2 class to gain acceleration on intensive timetables. Adams settled upon the 0-4-4T wheel arrangement to provide the basis of what was to become the O2 Class. The second of William Adam's 0-4-4 designs, the O2 Class was a development of his previous T1 class of 1888. The brief behind the design was to create a locomotive capable of mixed-traffic operations, a characteristic dictated by the relatively small wheel diameter and smaller cylinders, effectively to replace the obsolete Beattie Well Tank. As a result, a compact locomotive with high route availability was produced, a factor that would be essential during the later