The brand new Samsung Galaxy Z Fold 4 and Galaxy Z Flip 4 haven’t yet arrived on shop shelves, but some tech journalists and analysts around the world have the phone in for testing, so we’re discovering new features on the phones. The latest spot is a new battery life-saving feature that Samsung neglected to tell everyone about during its launch.

It’s a new ‘Light’ performance mode that you’ll find within the settings of both phones, and it’s designed to help save your handset’s battery life. In the phone’s settings, the feature says it “prioritizes battery life and cooling efficiency over processing speeds.” It also notes the feature doesn’t apply when playing games, and you can tweak that efficiency in the Game Booster feature on Samsung phones.

I’ve found the feature on my Galaxy Z Fold 4, and reports say it’s also available on the Z Flip 4. By default, the phone keeps itself on the Standard mode, and I can’t yet comment on its efficiency as I haven’t used the mode extensively. 9to5Google first spotted the feature, but a Reddit user who has the handset has dug deeper into the feature to see how it works. The testing was done with the Z Fold 4 alongside a Z Fold 3, and it found that even on the toned down Light performance mode, the latest phone could beat or match the performance of last year’s foldable.

The Snapdragon 8+ Gen 1 chipset inside the Z Fold 4 is 30% more efficient than the previous generation, according to Qualcomm, so if you want top-end performance, you won’t want to use this Light performance mode. That said, it’ll be a helpful feature for those opportunities where you need to save battery life. It’s currently unclear if this feature will come to other Samsung phones as part of One UI 4.1.1 or the upcoming One UI 5 update.