Popular 350ml classic design stainless steel double wall coffee cup is now given a new eco feature of natural bamboo outer wall which is made of sustainably sourced bamboo. It has a push on plastic lid with splashproof sliding closure and stainless steel ring matching stainless steel trims. Inner wall is made of 304 type of stainless steel and keeps drinks hot and cold longer. This cup is BPA-free and not microwave and dishwasher safe handwashing is recommended.