Package contents 20 x black hex nut/bolt dome covers, size M12 (fits 19 mm wrench) Why you need these Protects fasteners from rust, water and dust to extend service life and reduce maintenance. Improves appearance by covering exposed hex nuts and bolts. Simple plug-on protection that eliminates the need for frequent cleaning or repainting of fasteners exposed to the elements. Key features Material: durable PE plastic — strong, lightweight and not easily deformed. Weather-resistant: corrosion-resistant, aging-resistant, UV-resistant and low-temperature resistant for reliable outdoor performance. Function: shields nuts and bolts from moisture and contamination, reducing corrosion and dust buildup. Easy installation: press-on design for a secure fit; no tools required for mounting or removal. Compatibility and sizing Designed for M12 hex nuts and bolts and intended to fit a 19 mm wrench size. Please verify the hex cap and packaging size you require before purchase to ensure correct fit. Typical applications Automotive: cover wheel lug nuts and other exposed bolts to prevent corrosion and improve visual appearance. Outdoor equipment: protect fasteners on garden machinery, fencing, or outdoor fixtures from weather exposure. Industrial and construction: use on exposed bolts in machinery, scaffolding or metal structures to reduce maintenance needs. What’s included 20 pieces of M12 (19 mm) black PE hex nut/bolt covers. Please confirm dimensions and quantity before ordering to avoid mismatches.