Please note that this A1634 iPhone 6s Plus model is compatible with LTE bands 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 27, 28, 29, and 30 as well as TD-LTE bands 38, 39, 40, and 41. It is intended for many carriers in the United States (and sold optionally locked to AT&T), but it also was offered unlocked, contract free, and without a bundled nano-SIM for use on practically any carrier, T-Mobile, Verizon, and Sprint, for example), starting on October 8, 2015.

All iPhone 6s Plus models have a 5.5" (diagonal) widescreen pressure-sensitive "3D Touch" LED-backlit 1920x1080 native resolution (401 ppi) "Retina HD" display with "IPS technology and a taptic engine," and dual cameras. The rear 12 megapixel, 4K "iSight" camera has 1.22 micron pixels, an f/2.2 aperture, support for simultaneous 4K video and 8 megapixel still photography, and optical image stabilization for both photos and video. The front 5 megapixel, 720p "FaceTime" camera is more modest in capability.

The iPhone 6s Plus uses a 7000 series aluminum housing and is available in four metallic color options -- "silver," which has a white glass front and a silver colored back; "gold," which has a white glass front and a gold colored back; "space" gray, which has a black glass front and a medium toned gray back; and "rose gold," which has a white glass front and a pink-tinted gold colored back (pictured). It also packs a second generation "Touch ID" fingerprint sensor embedded in the "home" button.

The iPhone 6s Plus is powered by a 64-bit 1.85 GHz "Apple A9" processor and has 2 GB of LPDDR3 RAM and 16 GB, 32 GB, 64 GB, or 128 GB of flash storage (16 GB and 64 GB options discontinued and 32 GB option introduced on September 7, 2016). It also supports 802.11a/b/g/n/ac Wi-Fi with MIMO, Bluetooth 4.2, LTE (4G), and NFC for Apple Pay. It has a bottom-mounted headphone jack and uses a "Lightning" port to connect to a Mac, PC, dock, or power adapter.

Apple estimates that the iPhone 6s Plus provides "up to" 80 hours of audio playback, 12 hours of talk time on 3G, 12 hours of Internet use on 3G, 12 hours of Internet use on LTE, 12 hours of Internet use on Wi-Fi, 14 hours of video playback and "up to" 16 days of standby time.

In the US, this iPhone 6s Plus originally was available for US$299, US$399, or US$499 with 16 GB, 64 GB, or 128 GB of storage subsidized by a two-year carrier contract or unlocked, contract-free, and without a bundled SIM for US$749, US$849, or US$949. Apple also originally offered this model on a one-year "iPhone Upgrade Program" lease, which required the device to be traded in at the end of one year for US$37.45, US$42.45, or US$47.45 per month (which does not include the cost of mobile or data service).