If your mind is on your gear, then it's not in the game. Our CoMotion Series is designed to move with you, never against. Created specifically for wearing under your jersey, these shirts minimize friction and keep you comfortable so you can stay focused on what's important. CoMotion works like another layer of skin you won't even know it's there. CoMotion RC (Relief Compression) is a compression shirt made with Baseball in mind. You'll notice a little more compression where you want it (to keep your muscles warm) with relief where you don't (so as to not inhibit throwing or swinging ... you know, the important stuff).