R7-D4 has a white dome with brown printing for the various geometric shapes commonly printed on R-series units. The dome is printed on the front and the back, and along with the brown, features printing in other colours for certain gadgets on the droid such as black and grey printing for the photoreceptor (eye), a red circle processor state indicator, grey with black outlining for the holographic projector, and two squares for the logic function displays. On the back of the dome, several squares and rectangles are printed in black, light blue, grey and red for devices such as a secondary holographic projector and diagnostic display. The droid's body piece is brown and has printing on the front only. This printing is mainly white, but also has black and grey printing for representing things such as fold-out compartments (two thin rectangles on each side), an acoustic signaller and ventilation (two circular shapes inside the white rectangle, top and bottom respectively) and a power recharge coupling (gear shape in black square at the bottom of the piece). Attached to the body are two plain white legs.
R7-D4 was an astromech droid that commonly co-piloted Plo Koon's Delta-7B Jedi Starfighter, The Blade of Dorin. He accompanied the Jedi Master in several battles in the starfighter, including the Battle of the Kaliida Nebula and the Battle of Kadavo. Plo Koon refused to let the unit undergo memory wipes to avoid losing its personality and experience. he also piloted the Blade of Dorin during the Battle of the Kaliida Nebula. Before the battle, Plo Koon accompanied Anakin Skywalker, his Padawan Ahsoka Tano and Shadow Squadron through the Balmorra Run, in which they encountered Neebray mantas. Arriving near the Kaliida Shoals Medical Center, the squadron engaged the Malevolence, and were able to damage its ion cannons, and when they were used, they exploded and further damaged the Separatist warship.
- In preliminary images, this droid was referred to as R7-F5, reflecting the droid's original in-universe designation which was published in Star Wars: The Clone Wars: The Visual Guide before it was changed to R7-D4.