Method and apparatus for distributing print jobs. An unrestricted value associated with the stored-value instrument is authenticated at an instrument-authority system in response to an authentication request received from a merchant point-of-sale terminal. The units are particularly suitable for loading catalyst into tubes in a Fischer-Tropsch reactor. A front portion of the outer ring is longitudinally aligned with or overlapping the front end of the inner feed ring. Furthermore, the data transmitting and receiving devices according to embodiments will not need a reference voltage.