These weather instrument inserts are 72mm (just under 2 7/8") in diameter and mount in 2 1/2" holes. The included soft ring holds the instruments snugly in place.
The barometers are graduated in kilopascals as well as inches of mercury. The thermometers measure in both Fahrenheit and Celsius. Humidity, fortunately, is the same in both systems.
Available in either a modern-looking polished anodized aluminum bezel with easy-to-read high-contrast face, or with a traditional polished brass bezel and satin brass dial. These are ideal to mount for personal use or as a gift.