Frank Szmulowicz, Ph. D. Apr 23, 2014:

I see your point, mike23: it is generic purpose versus particular application. Clumsy we want not to be. Thanks.

mike23 Apr 23, 2014:

'Stojak na butle z gazem' or 'Stojak na butle z gazami'?
I think the first option. It sounds more natural. 'z gazem' is a general term/feature. Two many plural forms in one phrase are not necessary and might even sound clumsy. In some contexts they do appear in some they don't...
- filżanki z kawą (not 'za kawami')
- samochody z automatyczną skrzynią (z automatycznymi... sounds ok)