Starting today, new Amazon EC2 A1 bare metal instances are available. Similar to all other A1 instances, the new A1 bare metal instances are powered by AWS Graviton Processors that feature 64-bit Arm Neoverse cores and custom silicon designed by AWS.  

from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/10/introducing-availability-of-amazon-ec2-a1-bare-metal-instances/