Swift Gauge 2-1/4" Voltmeter.
Made in China
I would rate it 5 stars but there is no polarity information marked on the unit or any information included in the box. You have to guess the polarity and test to confirm. I guessed wrong. Reversing the polarity can cause damage to the meter movement. I was lucky and no damage occurred. One would think the folks that make the meters would provide this information.
First unit came without a needle or needle broken off. Makes you question its durability. Came without instructions.
No. Falcon instruments are not FAA TSO Approved. They are intended for use in experimental aircraft only.