1) Usually,the size you need=insole length=foot length(heel to toe)+(0.5--1)cm 2) Please select the correct UK# size according to your insole length by the Size Chart as below, Easy charge like your cell phone with the attached USB charging cable. Switch on the shoes when received and light up until all power gone.Then charge both shoes for 3 hours. Please NOTE: Please stay away from little kids when charging. Please do not immerse it in water. Please do not use it as running shoes. High-quality material, breathable, wear-resistant rubber soles, colorful LED light, which is the best gift for lovers and Mens for birthday, performances, Valentine's Day and other celebration., USE Instruction: Switch Button is hidden inside the pull strap on the heel.Press the button to turn on the light and change the lighting modes. Press the same button and hold for 3 seconds to turn off the light. What's more New design and technology LED light Up Shoes from Idea Frames! Cool sneakers light up your feet and catch all eyes on you while hanging out with friends. Best sneaker choice for dance party and music party! Night runners could also choose our LED trainers for breathable, endurable and safe wearing experience. Hidden Switch Button inside the strap on the heel. Easy to control the light on and off, at the same time the hidden button will not affect your comfortable wearing experience. USB charging for 2-3 hours will keep the light working for 5-8 hours.(Working period differs by different light up mode) Fiber Optic Cloth Upper Materials. Led Lights were applied into the upper cloth, which provides Higher Folding Endurance, water repellency and incredible lightweight.It could afford high temperature and water splashing, which reduces annoying troubles of broken light issues! High Abrrasion and Endurance EVA Outsole.New Fiber optic materials helps reducing the weight no more than 500g. Lightweight LED light up shoes for kids to have fun and also keep safety. Clean and Maintenance Instruction: Use Wet Tower to Clean the Upper directly. For stained and dirty spots, use the sponge eraser to brush the wet upper smoothly, and put the shoes in ventilated pacle to dry it. The shoes could afford water spinkling, but never soak in water. Idea Frames Led Light Up shoes could be the best gift idea! Choose the right size for your friend, lover and kids! The Shinning sneakers will be a nice present for birthday, halloween, thanksgive, christmas and Valentine's Day!