What iPad do I have. Model A1538

This is a Late 2015 model iPad Mini 4.

iPad mini 4

• Year: Late 2015
• Capacity: 16, 32, 64, 128 GB
• Model number (on the back cover):A1538 on the iPad mini 4A1550 on the iPad mini 4 Wi-Fi + Cellular
• White or black front bezel
• 7.9-inch Retina display
• Silver, space gray, or gold aluminum housing
• Lightning connector
• The nano-SIM tray is on the right side on iPad mini 4 Wi-Fi + Cellular
• FaceTime HD and iSight cameras
• Touch ID

https://support.apple.com/en-ca/HT201471

That's an iPad mini 4.

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