This is an adapter plate to connect an electric motor (specifically an Advanced DC FB1-4001 9.1" Series wound motor, though many traction motors share the same bolt pattern http://www.evparts.com/products/street-vehicle/motors--dot/96-to-192-volt-street-vehicle-motors/mt2119.htm) to a Honda B-Series transmission.
This would allow you to install an electric motor in a Acura Integra or a older Honda Civic SI and certain Civic Del Sols.
I'm installing it in a Honda CRX using some motor mount adapters and custom axles.
I have not yet bolted the whole thing together. I bolted the plate on the motor the other day and found that the spacer (that goes between the motor and the adapter plate) was a couple of mm to short, causing the ring gear on the flywheel to interfere with the bell housing. Hopefully, next week I'll be able to machine a new spacer and bolt the whole thing together with the clutch installed.
The bolt pattern appears to be spot-on though I may have to ream the clearance holes out a bit as the Honda bolts seem to have a larger shoulder than normal. One of the threaded holes is the wrong size which I will fix when I get a chance. It didn't end up mattering since the hole was oversize but the same pitch and I can just heli-coil it down to the right size.
So far, the centering of the input shaft on the motor shaft seems to be good.