https://www.techradar.com/news/goodbye-jack-apple-has-killed-off-the-last-iphones-with-35mm-headphone-sockets

Following the announcement of its 2018 iPhone range, which includes the iPhone XS, iPhone XS Max and iPhone XR, it's been revealed that many of its previous iPhone models, including last year's tenth anniversary iPhone X, are being phased out by Apple, as reported by The Verge. 

The discontinued handsets, which have now been removed from the Apple website, include the iPhone 6S and iPhone SE, meaning you can no longer buy an iPhone with a 3.5mm headphone jack from the Cupertino company.