The 42 Birds cork massage roller has special ridges that connect with the contours of your body to hit all the right trigger points to loosen up knots and restore soft tissues and muscles back to their original form. Similar to a deep tissue massage, the high density cork material helps apply the right amount of pressure on stiff muscles to help aid in relaxing and releasing tension. The dense cork material also allow it to maintain its shape— even after heavy use during yoga class or any fitness workout. Paired greatly with one of our yoga mats!