Machined alloy cap Material:70-30 CU-NI expension alloy (UNS C71500) High precision, thin wall Used for vacuum field Machined copper capsUsed for vacuum pumpMaterial: 70-30 CU-NI expension alloy (UNS C71500) Easy for welding with metallized ceramic, good sealing result with ceramic/glass, no leakageHigh precision dimension, 100% inspected, good appearanceCompetitive price