The product is designed to be both stylish and functional - when running in low light these leggings will light up when light is shone onto the material... Literally LIGHT UP. Perfect for winter / night running - both safe and stylish. The reflective material is also extremely flexible with a 2 fold stretch capacity providing maximal movement with zero restriction. These are unlike anything else you can buy today.(THIS EFFECT CANNOT BE FULLY SHOWN ON IMAGES) Small Size 4-6 Waist- 25"-28"