Which brake master cylinder do I need?
 

I'm trying to replace the brake master cylinder in my 10AE rx7 with no ABS. So I ordered a replacement but the unit they sent me only has 2 nipples for the brake lines on the sides. The unit in my car has a third nipple on the bottom near the front. Did they send me an ABS unit by mistake?

Yes, you got an ABS master cylinder.