This all silicone 12oz cup is 100% European grade silicone with an embedded stainless steel ring. It won’t collapse when gripped. The all silicone straw top and straw inserts for a tight fit and all parts are dishwasher and microwave safe. 

• Silicone cup that holds it's shape, no collapsing mouth 
• Silicone top inserts for a tight fit
• Can be boiled to sterilize 
• 100% silicone and 100% stainless steel ​ 
• Dishwasher and Microwave safe