1.Ball Screw Support Unit 2.BK,BF,EK,EF,FK,FF series 3.with Angular contact bearing ,good quality . 4. ... All types have stock . BK,BF Ball screw support unit :BK10 ... ,EF8; EK10,EF10; EK12,EF12; EK15,EF15; EK20,EF20.FK,FF Ball screw support unit :FK10,FF10; FK12,FF12; FK15,FF15; FK20,FF20 ...