Hmm -- maybe try a camping store? Montagne comes to mind of course, although it's kind of expensive -- there are some other camping stores around though -- there's a big one on Santa Fe at about Ravagnini -- just near where Sta Fe splits into Campos & Cabildo, and there is a chain that has shops around at Sta Fe between say... Billinghurst and Pueyrreddon (sorry that's not too specific) and they have another location on Medrano between Cordoba and Rivadavia -- again, definitely not specific but I'm just trying to remember based on what I pass in the car!!! The name is Kalimnos / Kaliptos or something like that! Hopefully someone else will see this post and it will jog some memories. Montagne has an outlet store just off of Cordoba as well, you should be able to find exact direction on their site. Sorry for the vagueries...