For Abs: Amazon Basics Abdominal and Core Exercise Workout Roller Wheel If you want to focus on your abs and core strength, get the Amazon Basics Abdominal and Core Exercise Workout Roller Wheel ($20). It's got ergonomic handles and a smooth-gliding wheel. Image Source: amazon.com Amazon Basics Abdominal and Core Exercise Workout Roller Wheel $20 from amazon.com Buy Now