Samsung is rumored to release a fourth member, the Galaxy S25 Slim, alongside S25, S25+, and S25 Ultra.The Galaxy S25 Slim is expected to be under 7mm thick, with an estimated thickness of 6.x mm.Apple's rumored iPhone 17 Air is said to be between 5mm and 6mm thick, potentially making it the thinnest smartphone.While the Galaxy S25 Slim may be showcased at Unpacked in January, rumors suggest it will be released later in the year.