BT HYBRID CONNECT Dongle

Does anyone know if the BT HYBRID CONNECT Dongle can be used with another network?
I have seen them for sale on Ebay, but don't know if they would work unofficially so to speak.

Im with BT just now for Phone, Broadband, and Mobile.
So even if it wouldn't work with another network, would it work with my BT SIM card in it?

Thanks in advance for any help