About the product:1. Bi-directional fingerboard sanding block for sanding frets and leveling fingerboards. There are two different rays on each block.2. Innovation design, each sanding block can tarnish 2 radius. 2 Radius of Sill Board used in construction and repair of guitar and bass: 7.25" & 9.5", 10" & 12", 14" & 15".3. Material: Maple. High gloss, durable and long-term use, not easy to deform. The groove side design provides a comfortable grip.4. Dimensions: 150mm*75mm*35mm. (5.9x2.95x1.38 inches). Convenient luthier's grinding block.5. Note: sandpaper included (grit 600). Different guitars need different bow grinding blocks, please confirm the size of your guitar or bass before you buy. Description:Material: Maple Dimensions: 150mm * 75mm * 35mm (5.9x2.95x1.38 inch)Matte Paper (600 grit): 146mm * 65mm (5.75 x 2.56 inch)Sanding Block Weight: 328g / 11.57oz Package Included:1 x Sanding Block2 x Sandpaper (600grit)Note: Please refer to the measurement. A small measurement error is acceptable within the normal range. There may be a slight color difference due to monitor, camera or other factors, please refer to the physical item.