what is this elec. part PLEASE ID???

[jmsmilin]

Its on my 250sx, but Ive seen it on most elec. start models, we are moving and book is packed otherwise I would look it up. I thinks its part of the ignition but Ive never had to work on this particular area before and am curious what it controls.
Thanx

[3 weelin geezer]

looks like an ingnition module to me.

[Mobular]

It's the regulator.

[ClayW]

voltage regulator.