There are similar products available from many automotive part retailers including Wal-Mart. Prices vary by quite a bit too.
I am using the Scan Guage II which does the same thing plus it monitors many engine functions like MPG, Miles to Empty, water/oil temp, battery voltage, RPM, etc, etc, etc. However the Scan Guage costs more too.
04 Winnebago Sightseer, 35N, W22 Chassis
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