M4 M5 M6 M8 M10 M12 Black Plastic Dome Head Bolt Nut Protection Caps Ideal for covering exposed Hex Head Fasteners such as Nuts Screws, Bolts offering a safe and professional finish. Also commonly known as nut protection caps, bolts caps and plastic caps. Dimensions: M4 CAPS - M4 Bolt & Nut Caps / Covers. Spanner Size: 7mm. Height: 8mm M5 CAPS - M5 Bolt & Nut Caps / Covers. Spanner Size: 8mm. Height: 10mm M6 CAPS - M6 Bolt & Nut Caps / Covers. Spanner Size: 10mm. Height: 12mm M8 CAPS - M8 Bolt & Nut Caps / Covers. Spanner Size: 13mm. Height: 15mm M10 CAPS - M10 Bolt & Nut Caps / Covers. Spanner Size: 17mm. Height: 19mm M12 CAPS - M12 Bolt & Nut Caps / Covers. Spanner Size: 19mm. Height: 20mm Right Product for Professional Job Our prices start from £22/1000 pieces