Product Advantages: With 18 Pieces Screws for mounting. (Each level has 3 Mounting Holes, 6 Pieces Leves = Total has 18 Pieces Screws. The holes are be used for screwing to a surface permanently). Size (Length x Height): 43x12mm =(4.3cm x 1.2cm) = (1.68 inch x 0.47 inch) . Package Included: 6 x Bubble Level. Circular Bubble Level with Screws Mounted, Domed Shape Multi-Directional Round Bubble Spirit Levels Measuring Tools. SIZIKJXGHWYI 6Pcs Circular Bubble Level with Screws Mounted, Domed Shape Multi-Directional Round Bubble Spirit Levels Measuring Tools