For anyone looking to stand out and recreate the perfect "V-Twin" style. Rizoma cylinder head covers are unique masterpieces of design, made using complex production processes and special 3D machining to achieve the most intricate detail. Each one is made from a single block of aluminum and machined down to a final weight of 1.2 kg. For anyone looking to stand out and recreate the perfect "V-Twin" style. Rizoma cylinder head covers are unique masterpieces of design, made using complex production processes and special 3D machining to achieve the most intricate detail. Each one is made from a single block of aluminum and machined down to a final weight of 1.2 kg.