Many thanks, some times I find that I come across something on the net and no matter how many searches I do I can't find answer's to the simple questions (the one that make you fell silly for asking). As for those other bottles I've found that the cylindrical shaped ones are a PITA to use in my small rucksack (I pack light and they don't stay where i want them)

PS: Sorry to keep bugging you like this but could you tell me the weight of the flask with and with out the cup please. Again, many thanks