E = Sony E mount, this requires 110 degree rotation from MFD to
infinity for G-lenses, which is a nice improvement. And the ring is
much closer to the lens, someone learnt deficiency of G->m4/3 adapter.
You can use Contax G-Biogon 21/2.8 with this adapter without
modifying/cutting its rear protector. Mount the adapter FIRST to the
Sony NEX3/5, then mount the lens to this adapter+NEX3/5 SECOND.