It is on the second tier of the Equipment Expertise skill tree and has five levels, each increasing the number of mines you can carry by one. They can be replenished by ammo boxes.
The damage caused by the mine instantly destroys anything less than a tank, no matter where it hits. However, damage varies on tanks depending on where the mine detonates:
On the front: 380-ish
On the side/top: 780-ish
On back corner: 950-ish (almost a insta-kill)
On the back: instant kill (1000)
Normal: Lay the mines before the vehicle comes in and blow it up. Can be used kind of like a motion sensor, telling you which base to defend.
Suicide: Run up to a vehicle and drop the mine behind you. when it runs you over, it runs over the mine next, giving you vengeance points.