Bhairava is sitting in Lalithasana and whereas Bhairavi is sitting in Ardha Padmasana. They are on hour-glass shaped base which in turn is supported by Bhadrapeetha.
For more details, see a related example of Bhairava and Bhairavi on this site.
The bronze is only about 7.5 cm in height. Their sharing the pedestal makes this special.
This bronze is most likely to be from North Karnataka. This may date to the nineteenth century or a bit earlier.