As far as bags and filters, bag is only required if cleaning up extremely fine dust-I use mine bagless with the exhaust port vented out my shed door)- (any generic vacuum bag would do-just measure the intake nozzle inside the drum and find a bag to suit-or tape one on ), there is an intake and outlet filter for the motor/blower, this is a woven plastic material-very similair to a 'Scotch-brite' pad, if you ever needed to replace it you could be shot first, drowned and after your re sussitated bodge new ones from similair material (these should never need replaced-unless your a complete F-wit)
Oh yeah, the internal pleated filter - wot JakeS said +1
you will be able to get spares anyway, its not like Lidl is a flybynight :wink: