This Sommer Cable coax (600-0551HF) is a low-loss 50 ohm RG213-type cable from the SC-Classic Series MKII, listed by Sommer as the HF400TT and RG213/LL. It is used for antenna feeds and RF links where signal loss matters, for example connecting wireless microphone and in-ear monitor systems to remote or directional antennas, radio and communications installations, and other fixed HF installations. The solid 2.74 mm (AWG10) oxygen-free copper centre conductor sits in foam-skin PE insulation, screened by aluminium foil plus a tinned copper braid for 100 percent coverage, inside a 10.3 mm black halogen-free PE jacket with high UV resistance. Sommer quotes attenuation per 100 m of 3.6 dB at 100 MHz, 8.8 dB at 470 MHz, 12.3 dB at 862 MHz and 13.2 dB at 1 GHz, with a velocity factor of 0.84 and 80 pF/m capacitance. It weighs 107.5 g per metre and is rated from -40 to 75 C. It takes standard RG213/LL connectors, such as crimp N or BNC types. Sold as bulk cable.