That's not him. It's his caddie, setting up some distance markers for a range session.

Check out these new Prototype Titleist MB (712 series) irons, custom-stamped with a simple "C," sitting on the range at Cog Hill. Who is the owner?

Here's your answer: Titleist Brand Ambassador Charley Hoffman.

Also warming up: Titleist Brand Ambassador Scott Piercy, with Cog Hill's famous red barn lurking at the back of the driving range.

Here's a close-up.

Out on the course, Titleist Brand Ambassador Scott Stallings winds up with one of his new Prototype AP2 irons.

Done and done.

Marc decided on the Golf Pride Tour Velvet full cord grips.

Passing rain shower. Don't worry, Titleist Brand Ambassador Rickie Fowler's clubs are staying dry.