The Sony Xperia Z4 never received a proper launch outside of Sony's home country of Japan, a move which seemed a little out of the ordinary considering they brought the former device, the Xperia Z3, to two different carriers here in the U.S. along with making it available online through Sony's official website. The Xperia Z4 went even more widely unnoticed outside of Japan for some consumers because it was known as the Xperia Z3+, and for those in the U.S. it wasn't available as a proper U.S. version. That has recently changed as Sony has now made the Xperia Z3+ available to purchase inside the country, and it comes with an official U.S. warranty.
Even with Sony's Xperia Z5 having been launched, a U.S. launch of the previous model phone inside the U.S. was expected and was confirmed, although you still can't pick it up straight from Sony, as the official US Sony store page simply leads to the B&H Photo site to pick up the device. Nevertheless, it's still there for any consumers who have been wanting to try a Sony device, and it comes with a U.S. manufacturers warranty that is good for one year from the date of purchase.
You can currently grab the Xperia Z3+ from B&H Photo for $499, although at the moment it's limited to just the Black and White models. B&H Photo does list the Copper, and Aqua Green colors as new items, though, and that they will be "coming soon" with regards to availability alongside the other two colors. When, unfortunately, is not listed, so if you were hoping to grab one of those two you'll have a bit of a wait. The Xperia Z3+ is essentially an updated version of the Xperia Z3, with at least one notable change. Sony have built it using with the Qualcomm Snapdragon 810 processor on the inside so it's a little more up to date than the Xperia Z3 when it comes to processing power. It still gets the same great two-day battery life as the original Xperia Z3, and it features the 20.7MP rear camera that Sony has been known for on more than a couple of phones. Of course, it's also waterproof and dust tight, so you don't have to worry about the elements.