fuel management with 4 dip switches

Any body have any info about a fuel management gauge with only 4 swithes on the back as opposed to six. I have seen the calibration diagrams for the six switch models. It is a duel engine gauge but I will will just be using it for a single engine boat. Any input would be greatly appreciated. Thanks -will

[boats.net]

The first three switches are for calibration(same as newer ones) the fourth is up for liter's per hour and down for gallon's per hour.