resonator (often called reso) is a leveled item in Ingress that is deployed on portals to capture and strengthen them.

Usage

Deploying a resonator on a neutral portal captures it for your faction. You can further strengthen a friendly portal by deploying more resonators until all eight of its resonator slots are occupied. Deployed resonators are visible in the scanner as small devices with colored beams connecting them to a portal. The color of the resonator and the connecting beam indicates the resonator’s level. These colors range from yellow (Level 1) upward to a dark purple (Level 8) for the highest possible. You can upgrade existing resonators, replacing them with higher-level ones, but only after all eight resonator slots are full.

Deployed resonators contain XM-based energy which is used to maintain the portal under your faction’s control. This energy decays by 15% of the resonator’s capacity per day, or can be depleted by enemy attacks. When a resonator runs out of energy, it is destroyed. When all of a portal’s resonators are destroyed, the portal is neutralized. There are several ways you can defend resonators from being destroyed:

Statistics

Level Energy Recycle
Value
1 1,000 XM 20 XM
2 1,500 XM 40 XM
3 2,000 XM 60 XM
4 2,500 XM 80 XM
5 3,000 XM 100 XM
6 4,000 XM 120 XM
7 5,000 XM 140 XM
8 6,000 XM 160 XM