Standard clone troopers use two types of armor: Phase 1 and Phase 2. In Legends, Phase 2 was a lighter and stronger improvement over its predecessor, while Phase 1 was superior in modern canon.

Same for Phase 2 Armor in Revenge of the Sith ... We also get the first appearance of Captain Rex in this scene, the clone trooper most loyal to Ahsoka, though he only shows up in the background.