For years, Nike teased the possibility of mass-producing the self-lacing shoes made famous by Michael J. Fox in 1989’s Back to the Future Part II. A replica shoe that was screen-accurate but didn’t self-lace was released in 2011; October 2015 saw Fox presented with a prototype that actually worked.

Now, fans of the series and sneakerheads are anxiously awaiting the pending release of the real thing. The good news? It’ll only cost you $10 to have a chance at owning a pair of the Nike Mags that were worn by Marty McFly. The bad news? It’s via a lottery system, and only 89 pairs are being made available.

Nike is currently accepting raffle entries through a digital storefront for the Mags, with all proceeds benefiting The Michael J. Fox Foundation for Parkinson’s Research.

The Draw, as the company calls it, began on Tuesday, October 4 and runs through October 11. Winners will be announced October 17, with exorbitant price gouging on eBay expected to commence moments later.

While it might seem like a paltry number of shoes, Nike probably realizes an entire line of space boot-looking sneakers aren’t for mass consumption. The adaptive fit technology that automatically sizes the sneaker for a custom fit is being eyed for the lucrative athletics market, with the Nike HyperAdapt 1.0 slated for release next month.

[h/t ABC]