Sports brand Adidas has unveiled its latest running shoes with springy blades sticking out of the soles (+ slideshow).
Adidas Springblade Razor trainers have 16 blades on the bottom of each shoe, arranged in pairs up the length of the base with two larger pads at each end.
Formed from specially engineered plastic, the blades compress under the runner's weight when pressure is exerted on the ground then spring back to help push the foot forward.
A sock-like upper wraps around the top of the foot to keep it secure when pushing off and is designed to aid breathability.
The men's trainers in four colourways are now available to preorder from the Adidas USA website, and will go on sale online and in stores across America tomorrow. They will launch in other countries later this year.
We've also published trainers with rubber loops on the bottom to give extra spring, which won the product design prize at a Swiss design awards last year.
Here's the information that Adidas sent to us:
Adidas launches Springblade Razor, the next generation of explosive energy under your feet. The new running shoe is available for pre-order for $180 on adidas.com this weekend starting Sunday 12 January.
Springblade, introduced last year, is the first running shoe with blade technology designed to help propel you forward. The Razor features a unique web design over sock-like Techfit technology that helps lock your feet in place and enhances breathability. The shoe's 16 individually tuned blades instantaneously react to any environment, compressing and releasing energy.
Springblade Razor goes on sale on adidas.com, at adidas Sport Performance stores and retailers nationwide including Finish Line on 16 January.
The Razor launches in four colorways for men, including Solar Blue/Tech Grey Metallic/Black, Black/Tech Grey Metallic/ Light Scarlet, Metallic Silver/Black/Light Scarlet and Light Scarlett/Black/Metallic Silver, and three colorways for women including Solar Blue/Tech Grey Metallic/Black, Black/Black/Vivid Berry and Bahia Pink/Metallic Silver/Black.