The 2500 series tanks are used for roll film and 4x5" sheet film. They are not designed for traditional inversion (hand) processing because they would use too much chemistry if they weren't used horizontally.
Sheet Film Kit (One-Reel) includes #2521 tank, #2512 4 x 5 Guide, #2508 Loader Base and #2509N sheet film reel. The #2509N reel allows up to six sheets of 4 x 5 film to be processed.
