iPad Mini 4
Also announced at the same "Hey Siri" press event in September 2015 that featured the debut of the iPad Pro was the iPad Mini 4 (left), which replaced the iPad Mini 3. Also seen here is the iPad Air 2 and the iPad Pro for comparison sake. The iPad Mini 4 was the first Apple device to ship with iOS 9 pre-installed and also was the first major redesign of the iPad Mini line, featuring a slightly taller and wider body. It also is much thinner than previous iPad Minis, matching the iPad Air 2's 6.1 millimeter thickness.