The AT-200Pro is a 200w capable auto tuner. It has 16,000 memory channels (memories recordable in 8 antennas per frequency). The tuner has two antenna ports on it, which are selectable from the front panel. The AT-200Pro is LOUD. If you aren't expecting the relays to slap when you first plug it in you may be quite startled. However, only the initial tuning sequence lets the tuner roll through all its impedance combinations. Once a setting has been acquired it is stored as a memory. That way when you go back to the same frequency (generally entire bands can be covered with one setting) the tuner knows exactly where to go - one click and it is tuned.

If your unfamulure with the operation of the tuner, take some time and watch these youtube videos linked below:

Tutorial Video Part 1
Tutorial Video Part 2
Tutorial Video Part 3