M4 M5 M6 M8 M10 Clip-On Nuts, A barrel with multiple threads ensures secure thread engagement. Also known as U-style clip-on nuts, these nuts firmly clip onto the edge of panels and stay secure. Carbon steel coated with colored zinc provide high corrosion resistance in wet environments. Product size: As shown in the figure. WARNING: CHOKING HAZARD -- Small parts. Not for children under 3 yrs.