All of our products have enough content for ~10-15 seconds of continuous spraying before they are empty. This is more than enough to aim and hit multiple attackers.
However, we don't recommend you testing the spray by pressing the trigger since it's important that you have the maximum amount of spray if you have to use the spray in an emergency.
If you want to test all other functions (location text messages, phone calls, siren and LEDs), you can push the TEST lever on the side of the product down for 10 seconds with something pointy. Then push the lever back up.