Thread Size: M4 M5 M6. - 【Precise Size】The M4 M5 M6 universal rubber well nut,sealed bolt holes to prevent leaks. Material: Rubber + Brass. - 【Excellent Material】High Quality Rubber with Captive Brass Nut,resistant to vibration and corrosion.Flange holds fixing flush to mounting surface.Sleeve compresses to provide secure fixing, even in irregular shaped holes.
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