Comparison : Item # KP3ALX, KP-A Series Control Ball Bearings
Item # KP 3AX, KP-A Series Control Ball Bearings
Item # KP 4AX, KP-A Series Control Ball Bearings
Item # KP 5AX, KP-A Series Control Ball Bearings
Item # KP 6AX, KP-A Series Control Ball Bearings