More than 15,000 pieces of Batman memorabilia, from vintage model kits to 1980s action figures to kites, will go up for auction Tuesday in Manchester, England.

It's the collection amassed over the course of 25 years by Steven Matthews, a 57-year-old hairdresser who acknowledges his interest in the Caped Crusader "quickly became an obsession."

"Every time I walked past what looked like a black and yellow Batman logo I’d have to stop and check it out," he told the Manchester Evening News. “Now that I’ve committed to selling them off it’s getting really hard to just walk away. I still get a nervous twitch every time we go shopping and I see something to do with Batman, but I’m just about managing to let go. My wife can’t believe how strong I am.”

You can see the full listing of memorabilia on the Capes Dunn auction website.