The manual compass is sixty-one notes from low A to high E. The tracker bar is configured for 58 note rolls. The key action itself is pneumatic not the customary pallet and sticker type. The note channels from the tracker bar simply intersect the channels between the key valves and the chest primaries. The chest primaries are covered with zephyr skin. These latter pouches generate the individual note actions by way of an Angelus type player action very much like the Angelus or later White Player Piano action.