Does anybody know what it is? There is no data anywhere, it looks like such thing doesn't exist.
However I have a box (250pcs) of those, 25V 220uF. They are quite big,
12.2mm diameter and 25mm high. Everything look pretty genuine. Black sleeves, clearly marked Rubycon RX-11. All writing is of very good quality, italic kinda handwritten 'Rubycon', '25v220uF' with real 'mu', not 'u'. They have _POSITIVE_ terminals marked with lines and circled '+' signs.It wouldn't have been worth asking if they have not been _THAT_ good.
All of them have at least 250uF capacitance and ESR is under 70mOhms (zic! under SEVENTY MILLIOHMS) that is really impressive for an aluminum 220uF capacitor. This is roughly the same parameters OsCons have but those are aluminum polymer so they are special.
Is it some Rubycon experiment with polymers? They have 2007 date code.
It can NOT be fake because they have excellent parameters far exceeding any other aluminum 220uF capacitor. They are objectively better than anything else and there is absolutely no data on those :(
Aha, there is NO temperature rating on them. Just 'Rubycon 25v220uF RX-11', line of '07 07 07...' and those '+' marks for positive terminal (that is longer than negative as it is supposed to be.)
I bought that box from Ebay couple of years ago, don't remember who was the seller. Pretty sure they were dirt cheap because I wouldn't have bought a box of those otherwise. They were gathering dust all that time until I decided to recap one of my Tek 2465BDV scopes and found them on a shelf. Didn't find any info so reached for my HP 4274A LCR meter and was stunned by the result.
Not that I do really need a datasheet on those, just out of curiosity. I do know they are outstanding capacitors far exceeding all those 'Ultra-Low ESR' ones.