This came up elsewhere around the web today and I had to share since it's approved for use in certified aircraft in addition to being useful, reliable, light weight and affordable.

From the manufacturer's website;
https://www.fdatasystems.com/gt-50
The GT-50 is a Clock, Timer, G-Meter, Voltmeter and Outside Air Temperature instrument enclosed in a milled aluminum case fitting in a standard 2-1/4” instrument hole. Priced at $169, it is a real bargain.
Thousands of GT-50’s are flying in experimental aircraft. Since FAA approval in 2013, certificated aircraft owners can also enjoy the GT-50’s capabilities.
Features

From the manufacturer's website;
https://www.fdatasystems.com/gt-50
The GT-50 is a Clock, Timer, G-Meter, Voltmeter and Outside Air Temperature instrument enclosed in a milled aluminum case fitting in a standard 2-1/4” instrument hole. Priced at $169, it is a real bargain.
Thousands of GT-50’s are flying in experimental aircraft. Since FAA approval in 2013, certificated aircraft owners can also enjoy the GT-50’s capabilities.
Features
- Instantaneous Display to +12/-10 G’s
- Records and Saves Max and Min G's
- Low Voltage Warning *NEW!*
- Extreme Operating Temperature Display
- Soft Orange Backlight
- 2-1/4" Panel Mounted
- Milled Aluminum Enclosure
- Weighs 2.5oz
- Includes Pre-Wired Connector
- 12-28 Volt Compatible