You can now launch the next generation general-purpose burstable T3-Standard cache nodes in Amazon ElastiCache. Amazon EC2’s T3-Standard instances provide a baseline level of CPU performance with the ability to burst CPU usage at any time till the accrued credits are exhausted. They offer generational advances in CPU performance that enable a higher overall baseline performance threshold over T2 cache nodes. 

from Recent Announcements: https://aws.amazon.com/about-aws/whats-new/2019/11/amazon-elasticache-now-supports-t3-standard-cache-nodes/