I haven't got a picture of them handy for you, but the original ones are fitted into the base of the wiper arm itself.
The squirter is a sort of cone-shaped affair, maybe 5/16" across, with a threaded section at one end and a pin-hole in the side of the top. The top of the 'cone' has a hexagonal head. (Will you recognise one if you see it from that description?
It's reminiscient of the screw-on fitting at the end of a capuccino frother on an espresso machine!)
So if you had ever wondered why there is a little grub screw in the wiper arm base, well now you know. The underside of the base unit has a metal tube attached to it that runs up to these tiny squirters. You attach the water hoses from the pump to these tubes. Note that all wiper bases have these, there wasn't a different base unit required for the accessory washers to be fitted. (Unless of course they've since broken off...)
There are also some original after-market types that screw through a single hole in the centre/rear of the bonnet with twin squirters coming out of either side of it.
Hope that helps,
RET