[Info-vax] Need special extention cable for power supply output

[tadamsmar]

I need another female socket so I can add an extra disk to a old alphastation 800.

I can find extention cords with one male and one female connector.  But I want one male and two female connectors.  I mean the usual 4 conductor power connector - disks have male 4 conductor connectors of this sort.

Where can I buy something like that?