To unlock the following items for Single Player mode complete the corresponding special objectives.

Unlock Electric Lock Pick:
Complete the primary objectives in JBA HQ 1

Unlock EMP Device - Enhanced:
Complete the primary objectives in JBA HQ 1

Unlock Hacking Device - Force Hack Upgrade:
Complete the primary objectives in JBA HQ 2

Unlock Frag Grenade - Attachment:
Complete the primary objectives in JBA HQ 3

Unlock Gas Grenade:
Complete the primary objectives in JBA HQ 1

Unlock Sonic Grenade - Attachment:
Complete the primary objectives in JBA HQ 2

Unlock Night Vision - Enhanced:
Complete the primary objectives in JBA HQ 3

Unlock Gas Grenade - Attachment:
Complete the secondary objectives in the Cozumel Assignment

Unlock Hacking Device - Software Upgrade:
Complete the secondary objectives in the Shanghai Assignment

Unlock Shotgun Shell - Attachment:
Complete the secondary objectives in the Okhotsk Assignment

Unlock Smoke Grenade - Attachment:
Complete the secondary objectives in the Shanghai Assignment

Unlock EMP Grenade:
Complete the secondary objectives in the Iceland Assignment

Unlock EMP Grenade - Attachment:
Complete the secondary objectives in the Cozumel Assignment

Unlock Explosive Sticky Camera-Attachment:
Complete the secondary objectives in the Iceland Assignment

Unlock Ultrasonic Emitter:
Complete the secondary objectives in the Ellsworth Assignment

Unlock Wall Mine-Flash:
Complete the secondary objectives in the Okhotsk Assignment

Unlock Wall Mine-Stun:
Complete the secondary objectives in the Ellsworth Assignment