Recon 

This perk helps in showing where the enemy is if you use flash grenades, emp grenades and concussion grenades. A good 3rd perk to use is sitrep, only because it shows enemy equipment and it makes it easier to find out where the enemy is. With hardline pro,you can show your team where the enemy is and they can help you get the 2 assists that you need to get that kill without putting much effort into it. 

The picture below shows what Recon does once you go pro and when it is at regular.