Sirius shared his idea with Hoare.

He suggested using a miniature replica to replace Harry during the summer at the Dursleys, allowing it to absorb the Dursleys' aura and then transfer it to Harry himself.

Hoare was speechless inside. Sirius, do you know that Dumbledore never directly told me about the protection spell? You've pretty much spilled all his secrets.

But this was just as well. Hoare had a question he had been pondering. Holding a pen with a thoughtful expression, he asked, "This absorption of Harry's—does it have a specific range?" He gestured, "What's the approximate diameter?"