Using 2 LNBs ?

[Michael Esser <Michael.Esser@gmx.de>]

Hi,

I've recently bought a switch for using 2 LNBs 
(viewing digital Astra + Hotbird), and on it's case is 
written '14/18 Volt Relais'. Unfortunately I have no clue
at all about sat-technology, so can anybody tell me if 
this is the right device (the salesman said it is -) ) and 
if so, how can I use it with the SIEMENS DVB card/driver ?

Thanks,
 Michael Esser.