Good information. I have been a Verizon customer for years but recently changed to Straight Talk. In years past, I used wifi calling to call/receive calls from the US. Straight talk does not offer calling outside the US (or US territories) and I understand that wifi calling will not work as well. So.....I'm looking at purchasing a phone to bring with me, purchase a local sim card and use this phone while in St. Maarten. I want to make sure I purchase a phone that will work with the local sim card. I know the phone must be unlocked. Does it matter if it is a GSM or CDMA phone? I understand GSM is used in most countries outside the US so I'm assuming that would be the choice. Do I need to worry about sim card size? Many sim cards now are sold with adaptors so they work in standard, micro and nano sizes. I do plan on purchasing a 4g LTE phone so that won't be an issue. Anything else I need to take into account when purchasing a phone? Thanks in advance.