Grenades / Mines / Explosives
hand grenade
smoke grenade
Claymore 
anti-tank mine
C4
Tools
Medkit (Assault class)
Defibrillators (Assault)
Ammo pack (Support)
Welding tool (Engineer)
Motion sensor (Recon)
SOFLAM laser designator / marker (Recon)
Mortar

Battlefield 3 will feature the 60mm M224 mortar for the first time. The mortar will be deployable by the Engineer class.
40mm shotgun

The 40mm shotgun, is an under-barrel accessory that can be used on a wide variety of weapons and assault rifles. In Battlefield 3, the 40mm will be usable with shotgun shells, frag rounds, solid slugs and Flechette rounds.
Grenade launcher

The grenade launcher is set to replace the M220 under-barrel launcher. It will support 40mm grenades, 40mm smoke grenades, and single-shot shotgun shells as well.
EOD Bot

The EOD Bot is a remotely operated robot which in Battlefield 3 will be able to arm MCOM stations, repair vehicles and disarm mines.
UAV

The UAV role will change drastically in Battlefield 3. Unlike previous Battlefield games, in Battlefield 3, the engineer will be able to unlock a portable UAV. The MAV Micro UAV is easily deployed and can be used to scout the battlefield and spot enemies.