Tiandi Hinge Style Unit: MM (1 millimeter ≈ 0.039 inches) Needle hinge style Unit: MM (1 millimeter ≈ 0.039 inches) Needle hinge style Unit: MM (1 millimeter ≈ 0.039 inches) Regular style Unit: MM (1 millimeter ≈ 0.039 inches) Slope style Unit: MM (1 millimeter ≈ 0.039 inches) 20 hinge style Unit: MM (1 millimeter ≈ 0.039 inches)