Olloclip iPhone 11 Elite Pack. Simply clip to your phone and attach the lens of your choice: Telephoto pro or Macro 21X (fish-eye). It also comes with a Bluetooth shutter release. Although marketed for iPhone 11, it fits my iPhoneXR, snugly - see photo of it on the phone and two pictures taken with it (telephoto and fish-eye). See photos with metal ruler, showing it will also fit iPhone 12 and 13 (as camera size & location are the same).
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