Flexible abrasive steel file / sheet FINE 280 x 51 mm (11" X 2"). Thin (average .5 mm .025").
Grit grade approximately UK 320 Grit. US 120 Grit.

This sheet can be bent to any shape, internal or external. Mount to your own T Bar or sanding block. Mount on your bench, to make a flat bed sanding area. Place sheets side by side for a larger area.
Complex curves can easily be fabricated. Cut using old scissors. Mount using glue or double sided tape.