heck the fuel level of any Jetboil canister before you leave the house with the Jetboil JetGauge. An easy-to-read digital output accurately displays a canister's fuel content, so you'll know whether new canisters are necessary for the trip. The JetGauge offers three settings to accommodate 100-gram, 230-gram, and 450-gram JetPower canisters. Plan ahead by determining how much fuel you will need for each meal using Jetboil's convenient usage guide. Although it's engineered for Jetboil canisters, the JetGauge is compatible with most isobutane/propane backpacking fuel canisters. Weighs 3 ounces.

See the demo video here:  https://youtu.be/zBipq-5SoUQ