When the weather gets cold, your gas blowback will usually find it difficult to fire consistently on regular green gas. But there is the Guarder Black Gas (also known as Power Up) that is in stock at Firesupport that many say is preferable to use in colder weather... "The most powerful GBB gas you can buy, the Guarder Black Powerful Gas now in stock.

£15 a can when you order at Firesupport."