The Pony Bottle Gauge is a tiny gauge that easily connects to the 7/16" threaded high-pressure port of your pony bottle regulator or other alternate tank regulator to show pressure in an easy-to-read display. Any diver who has used a pony bottle knows the hassle involved with trying to find out how much air is in the tank. Switching regulators to view the primary pressure gauge or adding a separate pressure gauge to the pony bottle is a problem solution. Now with the Pony Bottle Gauge, all those headaches are over. The Pony Bottle Gauge has a pressure range from 0 to 5,000 psi (350 bars) has an easy to read color coded display for at-a-glance pressure check, comes equipped with a high pressure O-ring so it's ready for immediate installation, and is a great accessory for any dive bag.