If you’ve ever wondered if there’s really something to this whole “dimensional transcendentalism” thing, a.k.a. the explanation given as to why Doctor Who’s TARDIS is so tiny on the outside but enormous on the inside, now’s your chance to find out for yourself. A TARDIS created for Peter Cushing for the 1965 film Dr. Who and the Daleks is getting ready to hit the auction block at Ewbank’s as part of its “Entertainment & Memorabilia” auction, which kicks off on May 31.

As any bona fide Whovian knows, Cushing’s “Doctor” is not The Doctor, though he’s based on the legendary Time Lord. Instead, he’s a man named Dr. Who, and he served as the protagonist in two feature films that were centered around the Daleks, an extraterrestrial race of mutant robots who are hell-bent on “exterminating” The Doctor and his many beloved companions. But the “movie” Daleks featured in the two Cushing movies are also slightly different than their small-screen counterparts, and as such, Dr. Who and the Daleks isn’t considered part of the official Doctor Who canon (though Russell T. Davies and Steven Moffat, who rebooted the sci-fi classic for modern audiences, have attempted to find ways to change that).

Wibbly-wobbly, timey-wimey semantics aside: the TARDIS that’s up for sale was created for that 1965 film, and is still a genuine piece of Doctor Who history. Here's how the official listing describes it:

"TARDIS originally constructed in 1965 at Shepperton Studios as a premiere model for the cast to emerge from onto stage. Inside it has a release plaque stating that it was removed from Shepperton in 1965 and many years later re-built by the BBC prop department for use at Children in Need 2009 at the Leicester Space Centre. There is a video of the TARDIS online of it entering the building for Children in Need. It has also been signed on the inside by Jennie Linden. It was sold on eBay as part of a charity auction in 2011 and has been stored since."

(You can see the prop in action in the aforementioned video below.)

Though this particular model was never featured onscreen, it’s still expected to fetch an impressive £8000 to £12,000 (about $10,500 to $15,900).

“Few TV programs have had as much impact on the British psyche as Doctor Who,” Ewbanks specialist Alastair McCrea said in a press statement. “It is no surprise that the series was revived for a new generation in 2005. Nothing is more iconic from the series than the TARDIS, so this really is a fantastic opportunity to secure a major piece of TV history.”