don't know why but my post didn't get posted so here goes again.
The frequency is 433.92MHz, its also referred to as 433.
And BBSB, Byron, HomeEasy and Domia Lite are not compatible with X10. Never have been.
BBSB is compatible with HomeEasy, Byron (who makes HomeEasy for B and Q), Domia Lite (which is not the same as Domia) and Klik on Klik off (Ikea has sold this in the past). There is another which I think is called Koopla or something, but this could just be part of the klik on klik off range.
The confusion comes from Domia Lite and the Domia range. The Domia range is X10 compatible.
Here is a
review that Automated Home did on BBSB. This also explains that it is not compatible with X10.