Blake 77776 Cast Iron Drain Ring.
77776 is likely the casting number, not the actual part number, it has been seen on some of these rings.
Blake is no longer in business.
There are no parts available that fit exactly because the drain bowl has a stepped bevel.
A Josam 22010 ring will bolt down but will only seal on the upper bevel.
O.D is 11-1/2".
Bolt-to-Bolt at 180° is 9"
These files are for identification purposes only.