Here is a video to tell you : What is SEAL Demo
S.E.A.L. stands for Safe Exchange Area Location. Within the app, while you’re in messages and speaking with another member, you will see a tab near the bottom the screen called “Location”. If you tap this button, 5miles will use your GPS to locate the nearest safe exchange locations designated by your city. These areas are typically well-lit and under surveillance. We recommend you take advantage of these safe areas to exchange your item and money.
Once you tap on a location, you can go to the top of the screen and tap “Send” which will forward this meeting spot to the other member in the transaction. You can both then tap on the location sent which will open in maps and guide you both to the safe exchange area location.