If they are single clip black bases they are Buzzball bases. If they are double clip Miggle made them. Unfortunately SIW is out of the black rookies.
I have a lot of them on many teams and they have made some great Rb's and Wr's over the years. The new Miggle black TTC's are excellent bases too. I have used MANY of them over the last couple years. They are excellent for speed.
RAIDERMAN