purpose of a lightning rod

{"cid":"91196577","title":"Transmission line Galvanized Steel Tubular Electrical Power Pole","imgUrl":"https:\/\/img.silkroadsl.com\/nimg\/0b\/5e\/6410d578f6d132db2b83f75c58ae-200x200-1.jpg","attrs":{"Price":"$222 - $445","Brand Name":"FUTAO","Model Number":"FTGG - 0 38 917","Minimum Order Quantity":"11 pieces","Delivery Time":"1weeks","Certification":"ISO 9001 : 2008","Place of Origin":"CHINA","Payment Terms":"L\/C, T\/T","Supply Ability":"150pcs\/days","Packaging Details":"40HC or OT, wrap by mat or straw mat","Height":"13M","Thickness":"4.5MM","Material":"Q235, Q345, Q420, Q460, Gr 50, Gr60, SS400, etc.","Shape":"Conical round","Color":"According to clients' requirment","Surface Treatment":"Hot Dip Galvanized","Welding":"AWS D 1.1"}}

{"cid":"91148787","title":"Transmission Line Electric Street Pole Anchor Bolt Q420 Polygonal 220KV","imgUrl":"https:\/\/img.silkroadsl.com\/nimg\/3c\/9b\/de7f65cc539826f6f6766c09f7d3-200x200-1.jpg","attrs":{"Price":"negotiation","Brand Name":"JSHG","Model Number":"HG-SP","Minimum Order Quantity":"One 40 HQ Container","Delivery Time":"1 week","Certification":"ISO\/CNAS\/IAF\/CA","Place of Origin":"China","Payment Terms":"L\/C, T\/T or Western Union","Supply Ability":"3,000 Metric Tons per Month","Voltage Grade":"10KV ~ 220KV","Thickness":"3.5mm","Shape":"Round \/ polygonal","Connection Structure":"Overlap \/ Flange connection","Application":"Electrical Power Transmission\/Distribution Line","Appearance Treatment":"HDG"}}

{"cid":"91185974","title":"ZXDW-3A 3A Large Scale Grounding Grid Earth Insulation Tester Strong Anti Interference","imgUrl":"https:\/\/img.silkroadsl.com\/nimg\/61\/fc\/626426b178b1462c48add4e19175-200x200-1.jpg","attrs":{"Price":"US $3999.00-$6987.00\/Set","Brand Name":"GDZX","Model Number":"ZXDW-3A","Minimum Order Quantity":"1Set","Delivery Time":"7-20 work days","Certification":"ISO9001","Place of Origin":"China","Payment Terms":"L\/C,T\/T,Western Union,MoneyGram,D\/A,D\/P,WeChat,Paypal","Supply Ability":"1200sets\/year","Packaging Details":"Packing wooden case or carton","Power supply":"AC 220V\u00b110%, 50Hz","Impedance measurement range":"0-150\u03a9","Resolution":"0.001\u03a9","Measurement error":"\u00b1(reading\u00d72\uff05+0.005\u03a9)","Maximum output voltage":"AC 420V (45Hz,55Hz, double frequency, sine wave)","Maximum output current":"AC 3A (45Hz,55Hz, double frequency, sine wave)","Anti-jamming capability":"Anti- frequency 50Hz voltage 10V","Dimension":"440\u00d7350\u00d7210mm3","Weight":"18kg"}}