The Altra HIIT XT 1.5 continues on the success of Altra's original cross-trainer with fresh colors and an improved upper. Designed with CrossFit and HIIT workouts in mind, it features a wrap-around, sticky rubber outsole for rope climbing and lateral traction. More cross-training specific features include the removable insole-without it the stack height goes from 24mm to 18mm-stitch 'n' turn stitching underfoot for a comfortable fit with or without the insole, and the stylish, durable upper. Built to perform, the HIIT XT is the perfect choice whether you want to hit the gym or run a lap (or both!). Experience the new shape of strength. Features: - Footshape(TM) Toe Box: Altra's FootShape(TM) Toe Box allows the toes to relax and spread out naturally and the big toe to remain in a straight position for maxium stability and power - Zero Drop(TM) Platform: Every Altra shoe features a Zero Drop(TM) Platform that places the heel and forefoot the same distance from the ground for natural alignment and a low-impact landing - PowerSole(TM): Removable insole that allows the shoe to drop from 24mm thick to only 18mm thick---what we call a 'Powersole' configuration, which allows for a firmer, lower to the ground platform - Stack Height: 24 mm - Weight: 8.9oz - Platform: Fully Cushioned Zero Drop(TM) platform and FootShape(TM) toe box - Last: SL2 - Midsole: Dual Layer EVA / A-Bound(TM) - Outsole: Rubber - Insole: 5 mm Sculpted Footbed - Upper: Quick-Dry Air Mesh - Other Features: Natural Ride System