It is having a Leak-proof lid with one hand push button operation. Its double wall vacuum insulation provides maximum temperature retention. With built-in tea hook it easilyholds tea bags or most loose tea leaf infusers. NS105BK004 Features: Made of BPA Free Material, Durable & Dishwasher Safe, Travel Tumbler, Holds up to 16 oz. TherMax® Double Wall Vacuum Insulation - Maximum Temperature Retention, Leak-Proof Lid - With One Hand Push Button Operation, Stainless Steel Interior & Exterior - Unbreakable"