TEMO Non Sparking Beryllium Bronze Copper Offset Box End Wrench Double Size of 18mm, 21mm, Length 280mm Beryllium Bronze (aka Beryllium Copper) is high strength, non-sparking, and non-metallic. Specialized applications include: hazardous environments, aerospace, musical instruments, and precision measurement devices. Product length is accurate but width and length are estimated based on current packing. The actual width and height are different. These bits are made to order with a 3-4 week lead time currently. Orders can not be cancelled once placed.