@juvela it was a sealed bearing BB and the collar tightens down to hold shaft from moving side to side. I am not sure how effective it was but it was their own thing. They were known for a double top tube BMX frame. Made the F/F, BB, and 6 bolt stems. I believe some bars as well. And were known for making the first Haro frames for Bob Haro that also rode one of their bikes and made some deals with them. All very collectible stuff.