A day pass costs £6.50 for zones 1 & 2 (Central London)
If you want to travel across all the zones it's £7.50
Do you know if it covers the Underground to and from Wembley Railway Station and can you link us this page, ta 8)
yes
a travelcard for the day in London covers tube, bus and overground train for £7.50
Edited. Please don't use this site to promote fraud. limpid
Whose promoting fraud?