Please refer to the installation video: https://youtu.be/Ux1sSA3LkIg ABEC bearing with less vibration, longer wear and a better roll,90A hardness wheels have more spokes for greater support and stability. TRIPLE SECURE CLOSURE , two micro-adjustable buckle and lace closure system easy to use, help fasten the feet properly into the skate enable a secure fit. PERFORMANCE LINER use EVA elastic cotton, also have a stretch band,flexible to adapt to different foot types,make the feet and shoes fit perfectly,breathable，comfortable,washable. INTEGRATED CNC SHELL SKATES Provide the fitness enthusiast and racer superior protection, Whether it is a simple outdoor recreation skating or a competitive racing. LIKU 3WD 125mm inline skates. It features unbeatable maneuverability and comfort. Our skates for the fitness enthusiast and racer looking to train, exercise or simply advance their technique with a skate that can be both a low profile and race skate.Rest assured, this is the ideal choice.