This story originally appeared on RealSimple.com.
Having a phone on you during a scary situation can be a lifesaver, but often, pulling out device to call 911 can compromise your safety. But with a new secret iPhone feature, help can just be a few discreet clicks away.
Related: Airbnb Is Making It Easier to Plan Your Next Group Getaway
According to a viral Facebook post shared by Travis Cena, a martial arts studio owner in California, your iPhone has a little known feature: discreetly calling emergency services. The post claims that if you hit your iPhone lock button quickly five times in a row, an emergency SOS slider will pop up on your screen. When slid, it will initiate a 911 call. As of writing, the post has received more than 350K shares and 62K likes on Facebook.
Related: Amazon Has a Kid-friendly Subscription Service That You Probably Didn’t Know About
Thankfully, this seemingly life-saving feature isn’t an internet hoax. In fact, it’s a new feature available for all iPhones running the new iOS 11. According to a page published on Apple’s website on November 2, 2017, Emergency SOS is available for all iOS 11 capable devices, but it’s only accessible via the five quick presses on iPhone 7 and earlier. For iPhone X, iPhone 8, and iPhone 8 Plus, one must press and hold the side button and a volume button to make the slider appear. An additional feature called Auto Call activates a personal security alarm that counts down aloud and calls emergency services when it gets to zero. For the new iPhones (X, 8, and 8 Plus), this can be accessed by continuing to hold down the side button and a volume button. For all other iPhones, this alarm will automatically sound when an emergency call is placed. If you would like to turn this off (and be able to discreetly place calls), just go into your setting and turn Auto Call off.
Related: Brilliant Christmas Tree Decorating Ideas From Instagram
All iPhone users can also let friends and family automatically know something has gone amiss by setting up emergency contacts. If you’ve set them up and an emergency call takes place, your iPhone will alert the designated contacts with your current location via text message once the call has ended. You can do this by opening up your Health app, clicking edit, and then pressing the green plus button under Emergency Contacts.
Hopefully this is a feature no one ever has to use, but knowing it exists and how to use it definitely can save your life.