Bob, what your looking at is a manifold filled with metering units. They control the flow of oil in a precision manner rated by the size of the internal orfice. On a Bijur style setup, like used in a common Bridgeport miller, each step up doubles the quanity, example, going from a FJB O to an FJB 1 means that the unit will flow twice as much oil. I usually replace them if the machine is old and I have it apart. Cheap insurance. And the smaller sizes hardly flow at all, even when new. A FJB 00, one size smaller than a FJB 0 can take several pump cycles to get one drop out! If they are Bijur units, check out Lube USA, much cheaper. Hope this helps.
Bill
