Overview Single-use cups cause a lot of waste – get a reusable mug from SIGG instead! Our Miracle thermo mug is made of stainless steel and is double-wall insulated, which keeps your coffee or tea hot or cold for hours. The mug is equipped with a secure button: push to drink and release to close. It's also leak proof: Perfect for beverages on the go as it's durable and free of harmful substances. Leak proof BPA free Sigg Miracle Mug 470ml - Brushed