That looks like a 35mm (no clue about inches here, sorry) standard non-flanged carto which has been punched using a carto puncher to be able to use it in a dct tank, a 50mm 'boge' flanged carto should fit in the larger tank thoughKels...get hub to measure them length-wise...in millimeters...then we can figure out what sized cartos to buy. Is that one of your cartos in the middle?