10 Sizes 200 Pcs Copper Gasket Combination, Copper Sealing Ring Combination Contains 30 Pieces of M5 x 9 x 1, 30 Pieces of M6 x 10 x 1, 20 Pieces of M6 x 12 x 1, 20 Pieces of M8 x 12 x 1, 20 Pieces M8 x 14 x 1, 20 Sheets M10 x 14 x 1, 20 Sheets M12 x 16 x 1, 20 Sheets M12 x 18 x 1.5, 20 Sheets M14 x 18 x 1, Enough for Daily use. Convenient Storage These Sealing Rings are Equipped with Storage Boxes, Which make the Gaskets Safer, More Convenient to Store, And easy to Sort. High-Quality Material Our Gaskets are made of High-Quality Copper Materials, Which have good Electrical and Thermal Conductivity, And can be Reused. Wide Range Of Applications Suitable for Electrical Connection of Water, Oil pan Plugs, Fuel and Hydraulic Accessories, Household and Commercial Electrical Appliances, Automobiles and Ships. Product Features Compared with Steel and Rubber Seals, Copper Gaskets have Stronger Sealing Properties and Higher heat Resistance. The Sealing Surface is Smooth, Which Helps and Reduces the Friction Between the Fasteners, Prevents Leakage, and Prevents Loosening or Dispersing Pressure.