Eco shield is an eco power in The Lost Frontier. The second green eco power and the sixth and last overall, it is received from a Precursor idol at the old Aeropan barracks, shortly prior to entering the facility and embarking on the mission "Search the barracks for seeker piece". At first it is a pure utility power, allowing Jak to cross pools of dark eco safely when walking over them. Its most powerful effect is that it provides a short but fool-proof form of invincibility. It is similar to the Light Shield power from Jak 3. Jak could also channel the shield around other objects, maintaining it around Daxter for around a minute at an increasing distance during the mission "Fight off the Aeropan shock troops".
Eco shield is activated by pressing + (for PlayStation 2) or (for PlayStation Portable). It then lasts for 7 seconds, though this can be increased with the increased shield time skill, which extends the duration by 3 seconds, ensuring at least 10 seconds of complete protection. Since it is incredibly powerful, it also requires the most eco by far to activate, nearly a complete bar, though this problem can be slightly mitigated with the cheaper shields skill.
For use in combat, it is most recommended to reserve it during difficult sections or tough enemies. As the shield acts like a hamster ball, reducing your traction when moving and not allowing you to use your melee skills, it does limit your offensive capabilities. The shield spikes skill slightly helps, but it only works on contact and deals relatively minor damage. Plus the aforementioned lack of traction makes for a poor tactic when trying to use it to ram enemies, though it does work well when an enemy comes too close.