Two types of PCI-e 6 pin connectors?

[woofercooker]

I just picked up a old cheap HD4870 GPU for retro gaming rig im building and i needed and extra PCI-E power adapter for the card i ordered one and just noticed the following in the advert.

PCI Express graphics card power cable with two molex 4 pin connectors.

Please note that there are two types of PCI-e 6 pin connectors, our connector has a square pin 5 (see pic

I am confused i never knew there were two types of 6 pin PCI-E connections. can anybody tell me what the difference is and will this work with my card?

 

[andybird123]

looking at pics of a 4870, you don't want a square middle pin, only 1 and 6, not 5 like they have
I don't know what that is, but its not a pcie connector