ITEM NAME:2Guitar Bass Radius Sanding Block Polishing for Fretboard Fret Leveling Luthiers img *{margin:0;padding:0;.Used for shaping a radiused fretboard and leveling installed frets. Wooden Fingerboard Leveling Sanding Block for Electric/Acoustic Guitar Bass. 2 Pieces Radius Sanding Block. Material: Maple Wooden.