Chris Bellamy, a footwear engineer, planned to take to the streets of Boston in the iconic event on April 16 in a pair of 3-D printed flip-flops that are allegedly comparable to traditional running shoes. Bellamy worked with Wiivv, a company that currently provides custom 3-D printed insoles, to design the shoes. A Kickstarter campaign for the sandals is already live, and Wiivv plans to introduce a full line later this spring.

The key to Wiivv’s custom products is the software in its app. From images that the customer takes of their feet, it can generate a perfect contour map that takes into account minute details like toe spacing. The result is a highly customized flip-flop shipped right to your door, without having to make a trip to the store for a fitting.

“We spent many sleepless nights driving fairly radical innovations in design and materials, and optimizing for biomechanics and comfort. So I am not worried at all about going the full 26.2 miles,” said Bellamy in a press release. “We’ve re-engineered every part of the traditional flip-flop to design the most comfortable, optimized sandal ever created, and I’ve had this marathon in the back of my mind through every decision we made.”