The asa5505 uses molex 2-pin 3mm connector with matching receptacle. Check this out for details:
https://www.newark.com/molex/145132-0203/cable-assy-2pos-rcpt-rcpt-11-8/dp/82AC4670
https://www.newark.com/molex/145132-0203/cable-assy-2pos-rcpt-rcpt-11-8/dp/82AC4670
http://www.farnell.com/datasheets/2707674.pdf
molex microfit 3.0 pin specifications
http://www.farnell.com/datasheets/1887331.pdf
Wire Insulation Diameter 1.85mm max.
Wire Size AWG 20, 22, 24
https://in.element14.com/molex/200875-0002/plug-housing-2pos-nylon-black/dp/2820620
https://in.element14.com/molex/43645-0200/connector-housing-rcpt-2pos/dp/3076015
https://in.element14.com/molex/46235-5003/micro-fit-fem-crp-lf-26-30-15au/dp/3010434
https://in.element14.com/molex/43030-0001/contact-socket-20awg-crimp/dp/1462526