... roller slider made of new pp and steel. 2.it's works your ABS ,arm,shoulder of roller slider. ... tone, and firm your muscles. Abdominal Fitness Equipment works your ABS, arms, shoulders and waist. Ab ... isolated, causing an effective extension and contraction of the AB muscles in your arms, shoulders and ... toward your knees, emphasizing the re-curling of your torso, and exhaling Warnning Always begin ...