The Spec Ops Pack is a pre-order customization pack available through Walmart or Steam (or GAME in the UK as part of a double pack which includes both the Spec Ops Pack and the DOOM Pack).
"Deck out your Brink character with new and exclusive customization options. Containing an exclusive weapon, a new scope attachment, a slick combat mask, and a unique "Dogtag" body tattoo, the Spec Ops Pack will put you amongst the Ark’s most elite warriors as you fight over the future of humanity’s last refuge." - Spec Ops Pack description
The Spec Ops Pack contains: