Boxing telescope

The punching telescope was a joke product developed by Fred and George Weasley in 1996 for Weasleys' Wizard Wheezes. It was kept in their old bedroom, but Hermione Granger went rummaging in their boxes and accidentally switched it on. It gave her a black eye that Molly Weasley was unable to remove.

When Hermione, Harry Potter, and the Weasleys went to Diagon Alley shortly afterwards, Draco Malfoy noticed Hermione's black eye and said he wanted to buy flowers for whoever did it. The group then went to the twins' joke shop, where Fred gave Hermione a thick yellow paste, which removed the bruise within an hour.

Appearances

 * Harry Potter and the Half-Blood Prince