Campaign Materials - Where do they all come from?

I’ve been reading up on the entitlement of a prospective parliamentary candidate to the use of Royal Mail delivery services.

In Brent East, a candidate is entitled to use Royal Mail to deliver 40907 items of campaign literature. What I’m not sure about is if that is in total (i.e. to all the households) or per ‘drop’.

There is further information on the Roayl Mail service to candidiate here. Or you could check out the Department of Consitiutional Affairs ‘guidance for electoral administrators and information on electoral legislation’.

If you have the knowledge perhaps you will share it here?