Archera Guaranteed Reserved Instances (GRIs) are standard 3 year AWS Reserved Instances & Savings Plans that Archera guarantees to either buy back or rebate any wasted spend at any point after a configurable term length. GRI term lengths can be as short as 30 days, and as long as a year. Archera GRIs have a premium associated with them that is reflected in the net savings rate of each GRI. Longer term lengths have higher net savings rates.