Smash Stainless Steel Wonderwall Flask 500ml - Assorted* Take your favourite hot or cold meals on the go with the Smash Food Flask! This vacuum insulated, dual-wall stainless steel food flask keeps food hot for up to 7 hours and cold for up to 9 hours. This reusable food flask is the sustainable option for packing hot lunches for yourself or your kids. No need to re-heat!