The gadgets in battlefield3 are all unique in anyway regardless on how their used and sometimes if these gadgets are use properly in the game it could change the tide of battle in a heartbeat. Heres a list of gadgets in the game of Battlefield 3.
Only used in the support class, the ammo box is a useful gadget for resupplying your teammates with endless amounts of ammo, however it regenerates explosives and rockets a couple of seconds slower then standard clips also it can be easily destoryed with any weapon from any player in the game.
Only used in the Assualt class, the health box speeds up the healing process for teammates as long as their near the gadget they can be healed until an enemy destorys it.
Only used in the Recon class, this discret little gadget can easily blend into any enviroment and it provides your team with intel on where the enemy is moving towards or away from the tug, however it can be fooled when a player starts moving slowly instead of sprinting or Driving.
Soflam [recon class only]
A mini-camera standing upright by a tripod it can be used for precision strikes or to spot enemies without putting the player at risk, however due to it's bright red light which designates on what it sees it can be destoryed by a enemy player or if an explosion destorys it when it's near a wall.