Microsoft Natural Ergonomic Keyboard 4000 for $29.99 shipped. Here is a screenshot for your reference. Alternatively, it is available at Amazon for $34.35 shipped. This keyboard features a 14-degree gable, 12-degree split and natural arc, along with 7-degree reverse slope for a more ergonomic design. As a comparison, Best Buy currently has this popular Microsoft ergonomic keyboard for about $49.