We recently told you about the Nike Air Mags, the ‘Back to the Future 2′-inspired shoes that pay homage to the footwear sported by Michael J. Fox’s Marty McFly in the blockbuster sequel.

Now, Nike has confirmed the Mags are real, but good luck getting your hands on a pair: In a ’BTTF’-inspired promo (which featured cameos from Christopher Lloyd as Doc Brown, Bill Hader as a shoe store staffer and Kevin Durant as a confused customer), we learn that only 1,500 pairs of the shoes have been produced and they’ll be going to the highest bidders.

In auctions that began September 8, the Mags — which, sadly, don’t actually self-lace but do feature some nifty LED lighting — are being auctioned off on eBay, with the proceeds going to Fox’s Foundation for Parkinson’s Research in the hope of “erasing Parkinson’s Disease from the time-space continuum.”

To learn more about the shoes, check out Back4theFuture.com.

Watch the Nike Air Mags promo below:

Get a closer look at the shoes:

[via The Daily What]