lnb is the satellite antenna, at centre of dish.
multi output types available from sat suppliers, see links section whis website.
Careful about fixing of lnb, there's sky type (bracket + pin) usually on mini dishes, and the other type (circular clamp), get right one for your dish, but they're electrically identical.
Use satellite grade cable, uhf type for tv aerials - from DIY stores - won't work.