An unlocked phone is a device that is not bound to any carrier or plan. It allows you to choose your phone first and your carrier second. Upon selecting a plan, simply insert the carrier's SIM card into the phone and you're ready to go. If you decide you want to change carriers down the road or want to take an international trip, it's as simple as replacing your existing SIM card with a new SIM and activating your new plan. Freedom: Choose the carrier with the best service or price. If you find a better deal later, you have the ability to change to a different carrier. Travel: Take your phone internationally and use the carrier of your choice. It's as easy as inserting an active SIM card. Selection: Choose the phone with the features you want, whether or not your carrier sells it, and get more service options without a contract. The first thing you’ll need is a SIM card for your desired carrier. When activated, the SIM card will let your phone connect to your carrier’s network. If you decide to upgrade to a newer unlocked phone in the future, you can easily remove the SIM card from your old phone and put it in your new phone—just make sure you get the right size of SIM card (nano, micro, or standard) for your phone. If you want to use your phone while traveling internationally, you can easily buy a SIM card for a carrier that operates where you’re traveling. As long as it’s activated, you can just swap SIM cards when you arrive at your destination. The Samsung Convoy 3 is built to strict military specs and can stand up to shock, extreme temperatures, dust, humidity and more. After all, when you’re on the job site, or the bike trail, the last thing you want to worry about is your phone.When you’re sitting in the office, any phone will do. When you’re out on the job, you need to make sure you, and your phone, sound crystal clear. With dual microphones and noise cancellation technology, the Convoy 3 lets you communicate clearly without skipping a beat.Sometimes, you need to talk to one person. Sometimes, you need to talk to a group. When you’re on the job, though, you’re always in a hurry. Thanks to push-to-talk, you can get the message out or start a discussion with just one push of a button.Got your hands full- With the Convoy 3 you can use voice commands to call, send messages and pictures, redial a number, or look up a contact.