Parts for Apple Early 2015 Retina 4K (4096 x 2304) Family

This model has a 21.5" 4096x2304 LED-backlit 16:9 widescreen IPS DCI-P3 "Retina 4K" display (that runs "pixel doubled" to look like 2048x1152). The rear of the case is aluminum and is thicker in the middle and tapers to a razor thin 5 mm at the edges.

Connectivity includes four USB 3.0 ports, dual Thunderbolt 3 (USB-C) ports, Gigabit Ethernet, 802.11ac Wi-Fi, and Bluetooth 4.2.

Compared to its predecessor, this model essentially has the same external enclosure, but it has a more advanced processor and architecture as well as dedicated graphics, a brighter display, and Thunderbolt 3 (USB-C) ports.

By default, the "Mid-2017" iMac models ship with a compact aluminum Apple Magic Keyboard and the multi-touch "Magic Mouse 2". For an additional US$30, you can upgrade from the default keyboard to the "Magic Keyboard with Numeric Keypad" for an additional US$50, you also can upgrade from the Magic Mouse 2 to the "Magic Trackpad 2," which provides multi-touch and pressure-sensitive "Force Touch" capabilities.