the mod works on ALL maxijets.
the ball joint holder works on the 400, 600, and 900. for the 1200 you will either need to glue it, tie it, or use those magnets
the algea free brand of magnet holder for the maxijet will work on ALL maxijets
the GPH is different for all the Maxijets, i dont know what the actual gphs are but there is a difference. i still have not seen an actual test.
the other mj mods out there like eco mods do have a greater gph due to the larger prop.
sure flow is to come out with a new model larger prop
eco mods are and have been found to have rust on their metal shaft.