No-brand T2 to Micro 4/3 adapter. Purchased on eBay.
Pros: Solid construction. T2 attachment can be rotated in its mount by releasing the set screws.
Cons: Black anodyzed aluminium rear bayonet, integral with adapter body. Interior is relatively shiny and may need to be painted flat black or lined with flocking to avoid flare and loss of contrast.
The T2 adapter is a successor of the T adapter. It has the same thread (42 x 0.75 mm, not compatible with M42) and registration distance of the T mount, and in addition allows the rotation of the threaded mount.