ever seen these RS 0,68 uf ?

[Xplorer]

Hello,

i'm wondering if some of you may have seen such Radiospares 0,68uf caps. i also have several silver mica RS, lemco ..
i kept aside the 500pf 500v etc for me, but there are still some values like this, but for a higher voltage, like 1kv or even 5kv. still squared, a little bit bigger. any good ?

[wrea398]

I've seen these on Ebay before but never in an amplifier. Just another part relabled for RS but I have no idea what company actually made them.

[Xplorer]

thanks !