Speed Lacing System makes it easy to get in and out of your skates; Vortech ventilation system channels air through the base, footbed and upper; Super-light, and super-comfortable inline skate design; Flex Lock acts as a stiffener in the locked position, ensuring firm support, while enabling increased flexibility when unlocked, enhancing preferred comfort; Extruded and machined 6061 aluminum; UFS 2 bolt frame for 4x80, 84, or 90 wheels and rockered set up options