Vacuum Flask 1) Capacity: 350ml, 500ml, 2) Material: 18/0 or 18/ ... stainless steel (as clients' request) 3) Double walls stainless steel vacuum insulated for maximum temperature retention hot or cold, can keep ... warmth for 24 hours 4) Lightweight, unbreakable, streamlined to fit into any rucksack, briefcase 5 ...