1. Features 508 pieces across 18 popular metric sizes (6x10x1mm to 24x29x2mm) including outer diameters from 10mm to 29mm and thicknesses from 1mm to 2mm. Provides full coverage for various pipe sealing and automotive repair needs. 2. Forged from premium high-purity aluminum material with excellent thermal and pressure resistance. Smooth, burr-free edges ensure superior deformation recovery, wear resistance, and long-lasting rust prevention under harsh environments. 3. Engineered for smooth torque distribution and proper elasticity. Deforms slightly under tightening pressure to create a tight, leak-proof barrier against oil, water, fuel, and hydraulic fluid leaks in automotive and industrial systems. 4. Packaged in a heavy-duty polypropylene (PP) transparent box with 18 separated compartments. Features a detailed size layout diagram on the top lid for fast, accurate size identification and clutter-free workbench organization. 5. Essential hardware kit for car engine oil drain plugs, brake systems, fuel lines, hydraulic valves, pressure lines, water pumps, and general mechanical maintenance. Perfect for professional mechanics and DIY enthusiasts.