Feature: Pre-bulbed design requires less installation load. Fastens in Blind Holes with Knurled Body for Anti-Rotation. Specification:Material: Carbon SteelFinish: Color-Zinc-PlatedThread Size: M4x0.7mmDrill Hole Size (+/-0.1): 6.5mm/0.26"Total Size: 18 x 11mm/0.71" x 0.43" (L*Max.D)Package Content:5 x Rivet Nuts