Big Mike's Fitness AB Slider Perfect Tool, Core Trainer Roller, 6 Piece Hits multiple muscles at once: When using the big mike's fitness AB slider, you are effectively training your upper and lower abdomen Spring-loaded roller: By having a spring loaded ab slider, you are able to focus more on your form and can be much safer Compact design: The big mike's fitness AB slider is compact and lightweight, making it perfect for traveling or carrying around Durable material: Made with heavy duty durable material that will keep up with your workouts Control is key: In order to get the best results, you should use it correctly