This is an Extra Super Fine Grit Sanding Stick from Squadron Products.
Extra super fine grit for polishing
Resembles a fingernail file
Can be used wet or dry
Can be cut and shaped to fit specific areas as needed to achieve the
finest finish possible.
One Extra Super Fine Grit Sanding Stick
Length: 5¾" (146mm)
Width: ½" (12.7mm)