Leak tight to 1 x 10-9 atm-cm3/sec He. Tolerance: thickness 25mm x 25mm (±0.0125mm), width & length (± 1.0mm). Tolerance: thickness 50mm x 50mm (±0.025mm), width & length (± 1.0mm). Hazards - Very Toxic. To maintain Vacuum tightness store and use in a dry atmosphere below 50% relative humidity. Typical analysis max. ppm: BeO< 0.6%, C 300, Fe 300, Ni 200, Ca 200, Si 200, Al 100, Zn 100, Mg 60, Cu 50, Mn 30, Cr 25, Mo 10, Ti 10, Co 5, Pb 5, Ag 5, B 3, Cd 2. Be 99.4% min. (incl. Be content of BeO). **End Use Statement required prior to shipment** This item may require a 'standard individual export license'. Please allow 10-20 days for this process.