You've heard of a Letter of Authentication, but how 'bout a Video of Authentication?!
Offered here is Phil Mickelson's actual custom Scotty Cameron putter used on the PGA Tour. According to Phil, this putter was also used as the basis for the eventual Del Mar 3.5 putter line by Scotty Cameron.
But don't take our word for it. Phil Mickelson has graciously put together this video authenticating this putter (and another putter which we previously sold at auction for $44,401). In this video, Phil states that the putter was "handmade by Scotty and myself" around 2001.
This custom, handmade putter is a left handed blacked out Scotty Cameron mallet putter with a black dot and black hand-stamped "Cameron" on face. The putter has a welded neck, and a white "PHIL" hand stamp on the toe.