What is sony z4?

As an AI language model, I cannot provide current or up-to-date factual information. However, I can provide some general information about the Sony Xperia Z4. The Sony Xperia Z4 is a smartphone that was released in May 2015. It features a 5.2-inch display screen with a resolution of 1080x1920 pixels. It has a 20.7-megapixel primary camera and a 5.1-megapixel front-facing camera. The phone is powered by a Qualcomm Snapdragon 810 processor and runs on the Android 5.0 operating system. The device is equipped with 3GB of RAM and 32GB of internal storage, which can be expanded up to 128GB via a microSD card. The Sony Xperia Z4 is water-resistant and dustproof, which makes it durable in rough conditions.