Supermicro CBL-0333L-01 Internal Power Extension Cable Connector: 6+2 pin to 8 pin GPU, 30cm. 18/20AWG
100% tested an end-to-end
6+2 pin to 8 pin Connectors
Internal Power Extension Cable Connector: 6+2 pin to 8 pin GPU, 30cm. 18/20AWG - RoHS and REACH compliant