... Durable, leak-proof and easy to clean Specification:Material: bottle:s/s 304(s/s 18/8) , sippy: siliconeThickness of raw material: 0. ... clamshell, double blister,etc. Features:Made of stainless steel with BPA-/lead-free alternative to glass and plastic bottles.Convertible ... Further pictures for reference: Baby feeding bottle (double wall )comes with high quality stainless steel and food-grade silicone