I do like a tatty plastic bag, me. This one came into my possession opened, but with an RBM rear derailleur inside it. This is a bit of a mystery, because I would translate the word ‘palanca’ as ‘lever’. Perhaps the bag was meant to contain gear levers - or perhaps in Argentina a derailleur is seen as a kind of lever - levering the chain from sprocket to sprocket.
At least the phrase ‘Industria Argentina’ provides conclusive evidence that RBM is an Argentinian brand.