Ten copper washer gaskets are provided in a pack of 10 for sump oil sealing and drain plug applications. Each washer is a solid gasket designed to form a reliable seal under typical engine and machine operating conditions. Quantity: 10 pieces per pack Size: outer diameter 29 mm, inner diameter 21 mm, thickness 2 mm Material: copper Type: solid gasket (crush washer) for oil sealing Function: designed to seal oil sump drains and related fittings Applications: suitable for engine oil sump drain plugs, gear/transmission oil sumps, and lubrication system connections Performance features: copper construction offers good conformability, strong seal under pressure, and resistance to heat and corrosion Compatibility note: intended for use with components and drain plugs requiring a 21 mm inner diameter and a 29 mm outer diameter copper crush washer Use cases Replacing the oil drain plug washer during routine engine oil changes to prevent leaks Sealing gear or transmission oil sump plugs in automotive or machinery applications Providing a copper crush seal for hydraulic or lubrication line fittings in small engines and equipment Advantages Reliable leak prevention with a deformable copper seal Durable in temperature oil environments Lightweight, compact, and easy to install Pack provides spare washers for maintenance and project use These copper washer gaskets are intended to align with standard copper crush washer practice for oil sealing, offering a practical, durable solution for automotive and machinery oil sump and drain plug seals.