UAG Surface Book Feather-Light Rugged [ICE] Military Drop Tested Laptop Case Fits ONLY the Surface Book [13.5-inch]. Does NOT fit the Surface Book with Performance Base & Surface Book 2. Armor shell and impact resistant bumpers. Dual lock secure screen closure. Detachable protection. Surface Pen holder. Meets military drop-test standards (MIL STD 810G 516.6).