The Bedknob is an enchanted knob that appears in the film Bedknobs and Broomsticks.
To keep the fact that Miss Eglantine Price is a witch a secret, the Rawlins children made a deal with her that they have something special, like one of her spells. So she gave them the traveling spell and cast it on a bedknob from the bed in their room. The object is to put it back on the bed, speak in a clear voice, tell it where you want to go, tap it three times, turn it a quarter to the left, and the bed will take you there. Paul is the only person who can use it.