Eisbaer for High End AIO CPU Cooling CES 2019 was a great time, but nothing says custom PCs like liquid cooling. We got the chance to see what Alphcool was announcing. For starters, we have the Eisbaer Extreme AIO. The big thing that separates this cooler from the rest is the solid copper radiator. Even if a cooler bypasses aluminum for the rad, a mix of copper and brass is often used to help reduce costs.