Invisibility Booster

• Type: Magical Device
• Owners: Weasley family (integrated into their Ford Anglia by Arthur Weasley)
• Maker: Arthur Weasley

The Invisibility Booster is a magical modification whose physical form is not described in detail. Its control mechanism, however, is a “little silver button” located on the dashboard of the Weasley family's enchanted Ford Anglia. When this button is pressed, the device is activated, rendering the entire vehicle and its occupants invisible.

The primary function of the Invisibility Booster is to bestow complete and instantaneous invisibility upon the object to which it is affixed—in this case, a Muggle car. It is powerful enough to conceal the large vehicle, its passengers, and their luggage from both Muggle and magical eyes. The device is activated simply by pressing the silver button on the dashboard. However, its performance is not infallible. The Booster is shown to be susceptible to malfunction, particularly after the car sustained heavy damage from its collision with the Whomping Willow. When failing, it causes the car to flicker in and out of visibility, making it a liability and increasing the risk of exposure.

The Invisibility Booster was one of several illegal enchantments that Arthur Weasley, in his fascination with Muggle artefacts, added to his family's Ford Anglia. In the summer of 1992, Fred, George, and Ron Weasley used the enchanted car, including its Invisibility Booster, to rescue Harry Potter from his bedroom at Number Four, Privet Drive. Later that year, after Dobby the house-elf sealed the magical barrier to Platform Nine and Three-Quarters, Harry and Ron used the flying car to travel to Hogwarts. They engaged the Invisibility Booster to avoid being seen by Muggles during their flight. However, as they neared the Hogwarts Express, the Booster began to fail, causing the car to become visible to several Muggles below. The malfunction worsened after the car crashed into the Whomping Willow, and the device ceased to function reliably. After ejecting its occupants, the semi-sentient car drove into the Forbidden Forest, its Invisibility Booster presumably still damaged.

The Invisibility Booster is a key plot device in Harry Potter and the Chamber of Secrets. It serves as a tool that enables crucial events, such as Harry's rescue from the Dursleys and his and Ron's alternative journey to school. Its subsequent failure is equally significant, as it leads to a direct breach of the International Statute of Secrecy. This breach results in a formal inquiry at the Ministry of Magic for Arthur Weasley and earned Harry and Ron detention. The device underscores Arthur Weasley's character, highlighting his professional interest in Muggle items and his tendency to bend ministry rules for his personal experiments.

• In the film adaptation of Harry Potter and the Chamber of Secrets, the silver button is shown clearly, and activating it causes the Ford Anglia to vanish with a shimmering, almost liquid-like distortion effect (film).