I searched on here and didn't see anything about it. Nothing much about it on Google either. Seems like an alternative to the S15 or Quaife LSD's if you want torque biasing and not fully locking. Balltec for R200.
eBay Motors: Balltec 240SX 2-way LSD R200 S13 S14 Silvia Drift JDM (item 200263098263 end time Oct-19-08 21:05:17 PDT)