The SVMS-01E Union Flag Graham Aker Custom (aka Graham Aker Custom, Custom Flag), is a modified variant of the SVMS-01 Union Flag in Season 1 of Mobile Suit Gundam 00. The unit is piloted by renowned Union ace Graham Aker.

Graham Aker's Custom Flag is a modified Union Flag that has twice the speed of a standard Flag thanks to a new high-output backpack and because it is lighter, which is due to the use of lighter armor material and because the suit carries less fuel. The suit also features an acceleration mechanism called the G-System which greatly accelerates the Custom Flag. However, the G-System has a large drawback; the suit's pilot will experience up to 12Gs of acceleration making it a double edged sword weapon.[1][5] Other modifications include reinforcements to the joints, a black anti-beam coating on the unit's surface for anti-Gundam battle and a new linear rifle designed by the Iris Corporation.[5] This Custom Flag would later be the base model of the limited production SVMS-01O Over Flag, which does not have the dangerous G-System system upgrade.

When the Over Flags are introduced, Graham exchanges the trial type linear rifle for the new standard-issue model (a triple-barrelled design consisting of a 200mm main gun and two smaller 60mm guns) used by the rest of the Over Flag squadron. The suit is then known as Union Flag Graham Aker Custom (Over Flag Specification), and can only be distinguished from a normal Over Flag by the blue stripe on its rifle (compared to a white stripe on the Over Flags) and the fact that the Custom Flag carries its rifle in the left hand and mounts its defense rod on the right arm (the reverse is the case for all other Flags). Graham's Custom Flag was later upgraded to the SVMS-01X Union Flag Custom II, by using a GN Tau Drive removed from the GNX-603T GN-X assigned to him. To intimidate enemies, all Flags possess an AI that programs the visor to make an eye pattern.