Normally you cannot make an OA with a Ranged weapon. The Sharpshooter PP allows you do just that though. It would be a Ranged Basic Attack, and I suppose it would still work with any feats you have that increase OA's. Additionally, since it's Ranged Basic, it will use your DEX score in the attack, rather than your STR score.
Edit: My bad, James is correct... The OA with a Ranged weapon will not provoke an OA. So essentially, it functions just like a melee OA but it allows you to use your nice bow/crossbow and your high DEX mod for the attack.