The Mass Inverter (Mass Imploder in the EU/PAL version) is a weapon used by Jak in Jak 3. It is the second dark mod Morph Gun weapon, and is powered by dark eco. It is acquired after the mission "Beat Cyber Errol boss".
The Mass Inverter mod is built on the basic Morph Gun frame, but has a purple and gray torus shaped object towards the front. It will release a field of anti-gravity energy, paralyzing its subjects as they float around in the air.
The Mass Inverter is unique in that does not really deal damage to undamaged enemies, instead it only deals damage to an enemy when that "attack" is certain to kill it. For example, if you hit a soldier and then activate the inverter while another is nearby then the damaged soldier will die when it dissipates while the other soldier will be okay and still be able to take one extra hit before actually dying. Repeated uses of the field on the same enemy will eventually kill it, presumably due to fall damage, enemies hit while in stasis because of the field will die as well. Due to the fact that the field only deals damage when it is the killing hit, enemies that die in one attack like the spydroid or stinger will always die as a result of the field. Lastly enemies can potentially float on their own and end up above water or a bottomless pit, when the field deactivates they will fall down and die as well. Enemies will not be able to attack while floating, although Marauder vehicles can still shoot and potentially harm Jak.
The inverter's anti-gravity field will automatically affect enemies traveling into the field, their momentum also affects their traveling speed through the field itself. When fired the field will rapidly expand outward, where after it settles and it slowly expands a little further. It can be useful to effectively bottleneck an area, forcing enemies to enter it although it is best used in the midst of a group of enemies for immediate effect. Bullets and such do travel freely through the field, so be careful not to be attacked by a ranged enemy who is still outside the range of the stasis effect.
Once the field has been deployed you can either run away or use the opportunity to take down the harmless enemies. Either the Beam Reflexor or the Needle Lazer are best suited for this job, the impact of the bullet will oftentimes also ensure the enemy flies away and dies elsewhere. An attempt to fire it twice in a row will automatically result in Jak equipping a different tier one weapon, as long as you have ammo for that type of mod. The Mass Inverter will not affect bosses.