If you apply this upgrade, your shield will not be penetrated by pulse cannons, sabot torpedoes and tandem torpedoes, which normally bypass (or partially bypass) shields.
- Pulse cannons will deal all damage to your shields (and none to hull).
- Sabot torpedoes will do no damage at all.
- Tandem torpedoes deal their "shield damage" + "hull damage" to shield.
However, this upgrade also decreases your shield HP by a given percentage (about 60% for legendary shield reinforcers, more for lower rarities). This percentage stacks with Shield Booster multiplicatively.
Example: if you have 1 000 000 shields and you install a -60% Shield Reinforcer and a +100% Shield Booster, you'll have 800 000, not 1 400 000 shields.
This upgrade also greatly increases the time that must pass after your ship was shot at, until your shields start recharging (from 30 seconds without this upgrade, to about 2 minutes, depending on rarity).
This does not protect from EMP torpedoes