I know many of you are experts in fluorescents, so may I ask,.. what is the type (name) of this holder and or type of fluorescent lamp required? Note the ballast is below the lamp holder (not CFL) and I was told has written 0.34 amp, E121467 Flourescent. Thanks!

That appears to be a g or gx23. The g lampholder takes a lamp that has a single ridge on either side and the gx lampholder takes a lamp with two ridges on either side. Hope this helps.

Thoroughly confused. What about the ridges on the same side as the pins? Anyone else? 0.34 amps = what wattage?

here you go. Some makers use a regular 14-20 choke and some use a special pl13 choke.

Looks to me like its for 13W Twin Tube (called by manufacturers under trade mark names TC-S, PL-S, LYNX-S, DULUX-S, BIAX-S etc), atleast thats the only lamp i know of that uses the GX23 and not the G23 base

The Twin Tube lamps have higher arc voltage than the T8/T12 lamps of comparable power, so they will draw lower current than the rated T8/T12 on the same ballast

Im not sure if you got there an example of the same thing, but it could well be

I am from the 240V/50Hz world, so the example i know is : There is the 18W T8 / 20W T12 fluorescent ballast (here its not intended for 14/15, that require their own choke. The 18W T8 is drop-in retrofit lamp for 20W T12, same length, works on same ballast). The ballast is rated for 18/20W at 370mA. If used with 26W TCD it will work at 325mA, which is the correct current for the 26W lamp, and really power it at 26W, allthough not rated on the ballast

If I remember well, the US PL-S 13W has two notches on each side (the 5..9W and the European 11W have just one notch on each side).
PL-S 13W means 0.22A arc current.