This is a fully legit Counter-Strike 1.6 anthology Serial! Delivery instant via the Autokey system.

Note:
These keys are for registration with a steam account from steampowered.com!

Includes:

Counter Strike
Counter Strike Condition Zero

• Counter-Strike is the 1 online action game in the world. Engage in a realistic brand of counter-terrorist warfare in this popular team-based game. Take out enemy sites. Rescue hostages. Your role affects your team's success. Your team's success affects your role.
• Counter Strike: Condition Zero advances the award-winning series by introducing single-player action and special enhancements for online play. You take the role of a counter-terrorist in an ongoing campaign to defeat terrorism attacks around the globe
• As a squad leader in an elite counter-terrorist operative, use specialized maneuvers and weapon skills to complete over 18 brand new missions, each containing numerous objectives.