what gauge extension cord for generator

{"cid":"91181013","title":"Universal Generator Auto Retractable Extension Cord Reel , Flexible Power Cable","imgUrl":"https:\/\/img.chinax.com\/nimg\/83\/5d\/93602c5aae8a60a81ac321ba411d-200x200-1.jpg","attrs":{"Price":"Negoation","Brand Name":"SFC","Model Number":"SFC-GFCI-02","Minimum Order Quantity":"100PCS","Delivery Time":"25Days","Certification":"ETL","Place of Origin":"Jiaxing,China","Payment Terms":"T\/T, LC","Supply Ability":"10000PCS Per Month","Packaging Details":"every one into plastrics poke and box. 5pcs into paper CTN.","Material":"ABS , PA66 UL94V0","Rating":"20a,125vac, 30A 125VAC","outlet quantity":"20A 125VAC GFCI duplex outlets","Color":"Black|Yellow","Power Cord Length":"15 ft","Cord":"UL approved 10AWG"}}

{"cid":"91224791","title":"50 Amp RV Power Cord with 6 AWG Copper Conductors and NEMA 14-50 Connectors for Heavy Duty Use","imgUrl":"https:\/\/img.chinax.com\/nimg\/66\/2d\/6ed620271eee2ada0674c8f2c221-200x200-1.jpg","attrs":{"Price":"10 USD -15 USD","Brand Name":"kenhon","Model Number":"50A RV cord","Minimum Order Quantity":"1 sets","Delivery Time":"7-15 days","Certification":"UL Listed \/ CSA Certified","Place of Origin":"Shenzhen, Guangdong, China","Payment Terms":"L\/C,D\/A,D\/P,T\/T","Supply Ability":"Can produce 10 million sets of wire harnesses annually","Packaging Details":"10*10*10","Conductor material":"pure copper","Insulation material":"Teflon","Rated voltage":"250V","Current rating":"50 Amperes","Max power output":"12,500 Watts","Wire gauge":"6 AWG","Conductor count":"4 Conductors","Temp. range":"-50\u00b0C to 105\u00b0C"}}