In the weight-obsessed sport of professional cycling every ounce counts. This incredibly simple premise prompted Giro, a company that makes bike helmets and shoes, to design what could be the lightest cycling shoes ever. The company’s new Prolight Techlace model is so light that designers believe that they can shave precious seconds off a pro rider’s time.

When designing the new Buy Now , Giro incorporated carbon fiber elements into the shoe’s design to help provide stability and shape to the sole without adding much in the way of weight. The Techlace also does away with the replaceable rubber sole pads used on most other cycling shoes, choosing to go with built-in pads instead. That decision alone reportedly shaved 10 grams off the weight of the shoe, which saw further improvements by switching to a unique closure system that blends both Velcro and traditional laces. A highly breathable mesh fabric is melded with Giro’s proprietary Teijin synthetic materials to create an extremely lightweight upper as well. The result is a shoe that weighs just 150 grams (5.29 ounces), which is nearly half the weight of Giro’s entry-level Treble II model.

So how do all of these improvements to the shoe translate to better performance out on the road? Giro estimates that had Australian pro cyclist Richie Porte worn the new Prolight Techlace while riding up France’s Alpe d’Huez — one of the most notorious climbs in all of cycling — while competing in the Criterium du Dauphine a few weeks ago, he would have shaved 15 seconds off of his total time. Considering that Porte currently trails Chris Froome by 39 seconds in the overall standings at the Tour de France, it becomes clear just how precious those seconds can be. American rider Taylor Phinney was also wearing Giro’s new shoe when he won the polka-dot jersey during stage 2 of the Tour as well. That jersey is awarded to the best climber in the race.

As you might expect, the Prolight Techlace shoes do not come cheap. Giro is selling them for $400, which is well above what most casual riders will spend for their footwear. But for cyclists who are on the lookout for ways to cut weight from their gear, these new shoes will be very enticing.