The 350 ml Transit Fliptop double-walled recycled stainless steel tumbler with vacuum insulation is made with premium technology that makes it 33% lighter than standard stainless steel. Featherweight spun-steel insulation keeps drinks hot for 4 hours or cold for 6 hours. The tumbler is leakproof and has a matching silicone at the lid tab and footpad which makes opening, closing and setting it down quieter. Dishwasher safe and compatible with most car cupholders.