X bionic sphere running vest mens this x bionic sphere running vest mens features a sleeveless design with a zipped fastening and the 3d bionicsphere system to the back that guarantees optimal temperature regulation to the jackets interior running vest sleeveless zipped fastening securely closing back pocket reflective detailing highly elastic microdiffuser 3d bionicsphere system x bionic branding machine washable main fabric 100 polyester insert