SIZE SUGGESTIONS: Please measure heel to toe length and choose size according to followings. 6.3(inch) foot⇒size: 10 Little Kid/ 6.8" foot⇒11 Little Kid/ 7.1" foot⇒12 Little Kid / 7.4" foot⇒13 Little Kid/ 7.8" foot⇒1 Little Kid/ 8" foot⇒2 Little Kid / 8.5" foot⇒3 Little Kid/ 8.7" foot⇒4 Big Kid/ 9.1" foot⇒5 Big Kid/ 9.5" foot⇒6 Big Kid/ 9.75" foot⇒7 Big Kid. PLEASE PURCHASE BIGGER SIZE IS BETTER THAN SMALL SIZE IF YOU ARE NOT SURE. Please pay attention to the following before choosing a size. The '10 Little Kid' size is the SMALLEST, and the Little Kid size is getting larger in the order of 10≪11≪12≪13≪1≪2≪3. Big Kid size is getting larger in the order of 4≪5≪6≪7. The '7 Big Kid' size is the LARGEST size. You can pop up and hide roller by a button at heel. So you can use this both of roller skates shoes and normal sports shoes. These skates shoes are great- comfortable fit- sleek style too. High Quality material, breathable, wear-resistant rubber soles, colorful LED light, which is the best gift for lovers and kids. The on/off switch is inside the shoes. You walk on the road , the shoes light up automatically. Amazing Light-up LED, sneakers soles light up in Colors! The battery can not be replaced and recharged, the battery can use about 3 month. SDSPEED is the company from Korea - Home country of BTS , we try to satisfy the customers' needs and expectations. Please COMPARE and ENJOY our competitive PRICE, QUALITY and CUSTOMER SERVICE. We are proud of our Price Competitiveness (be evaluated by Amazon) is 100% across our All Listing Products on Amazon.