Expansion Grenade

This expands you when you are almost next to it upon detonation. When expanded you are completely invincible to attack. You will instantly kill weaker enemies that you come in contact (including traps and turrets) and damage the Overlord. Structures like spawners are not affected.

Your normal weapons will be disabled while expanded.

Tips:  
 * 1) If you have a status effect that is going to last a long time, then the expansion grenade will remove those effects
 * 2) Your 9-inch Waste Disposal Cannon is much more powerful when expanded - especially with high level WSR
 * 3) Not-A-Shoryuken is more powerful while expanded
 * 4) You can use your Grenade Reformer to get multiple sessions of invincibility per mission

The expansion grenade is found inside the top right computer on level 31.