SPEED FORCE II - Speed and Power with Barefoot Feel If you&&';;re looking for the closest thing to a true barefoot experience, look no further than the Speed Force II - a stylish upgrade to our original Speed Force. Steven Sashen, our CEO, Co-Founder, and Masters All-American sprinter designed the Speed Force with a former Nike developer. It&&';;s the shoe he trains and races in. Since we released the original Speed Force, people have worn this ultra lightweight shoe for working out, pickleball, taking a stroll and everything in between. More Breathable and More Stylish Speed Force II is our lightest performance shoe, weighing in at 6.5 oz. per shoe (M9). If you take out the removable insole for an even more barefoot feel, the shoe weighs even less! The biggest change: a new, elegant, super-breathable upper with welded components for extra durability. A Secure, Barefoot Experience The iconic, adjustable instep and midfoot straps are not only eye-catching, but functional, giving you a confident, secure feeling for whatever you do in the Speed Force II. With a flexible 4.5 mm thick FeelTrue(TM) rubber sole, your brain gets the feedback it needs to help you move effectively, efficiently, and enjoyably. The dual chevron tread grips the ground and, like all Xero Shoes, Speed Force II is backed with our 5,000 mile sole warranty.