The plasmite bomb is a type of explosive used by Jak in the "Blow up strip mine eco wells" missions in Jak II. They are heavy, gray metal spheres and once activated open up along the middle and emit a red light. Vin asked Jak to use a number of these to destroy six eco wells at the strip mine, but due to an accident by Daxter they were all forcefully activated. After entering the strip mine the time limit is at two minutes.
To dump the bombs into the eco wells Jak had to use his JET-Board and cruise up each ramp in front of each well at high speed to reach the altitude needed to drop the bombs inside.