The Kathryn Units are one of the distinct strains of clones created by The Collective to form a part of their Labour/ Military force. Kathryn Units specialise in Medical Assistance. Some of their enhanced abilities include in depth knowledge of clone and natural-born biology, fist-aid and triage and basic surgical procedures. Kathryn Units are known for their swift action and pleasant bedside manner. Kathryn units were commissioned as a replacement for the Olivia strain. Improvements were made to the unit's temperament as well as functional and cosmetic alterations to its biology.