Marathon's Atomic Backlit Desk Clock, with Heat & Comfort Index is part of Marathon's new elite line of clocks. Not only does it have the regular features you would expect to see in a clock (time, day and date), but it also features indoor temperature and humidity. You can also switch between a heat index and comfort index that depicts how current conditions compare to ideal conditions. This clock is perfect for an office setting where indoor conditions such as temperature and humidity can be linked to productivity.