The usual makeshift tool for parallel scribing was a pencil stuck at one end of a block of wood that was hand-held parallel to the wall profile, which, if you were lucky and with the wind in the right direction, left a drawn line to cut to that somewhat matched the profile of the wall.
The Perfect Butt removes the element of luck and skill from this process. The unique solution is that the scribing pencil is held at the axis point of a wheel, which guarantees a constant distance between profile and scribe point. Cut to that line and you'll find a perfect match between wall and work surface.
Woodworkers have found it great for proportioning details during design layout, giving five different scaled-up offsets, not to mention offsetting the forms for bent-wood lamination.
The tool features five different quick change wheels, an included sprung pencil to ensure constant contact pressure, and a solid brass counter bored retaining shaft.
The Profile Scriber retails for approximately $30 and is available at KMS and The Tool Store.