SAPPHIRE Unique Custom construction using ultra-high-purity oxygen-free copper in different diameter and types Custom Plugs: Copper-silver alloy with gold-plated contacts: A - B type Hand wiring Hand trimmed with calfskin to reduce the microphonic effect, cause to change the capacity. The capacity influences the transmitter frequencies. Available in lengths: 30cm, 50cm, 1m, 2m and 3m