A three axis digital readout system by BW Electronics. Based on a mechanical encoder system, with a stainless wire on a spring-returned barrel.
One encoder looks fine, the other is sluggish to return and leaves about 4 inches or wire sticking out - whilst the urge to give it a quick spray with WD40 was almost overwhelming, we've left well alone... Display unit is complete with main adapter, it all appears to come alive when powered up.
BW have a website here which gives details on these units.
Complete with manual.
