WTF is that? speedodrive sender adaptor thingy....

[fax0815]

Hi,
recently took this of an import AE86, was fitted between the speedo output on the gearbox and the speedo cable going to the dash. Unfortunatly no partnumber or anything on it, the wires are in Toyota colours (black red dots, green red dots, red) but the plug doesnt look like anything I´ve seen on a toyota before.
Its not a converter, 1 turn on the input causes 1 on the output.
What could it be?
The car was a late GT APEX so I asume it might have had a digidash, but the digital speedsensors on google look different.

Any ideas?