Achieves extreme thermal efficiency to keep hot drinks hot and cold drinks cold for longer with a lightweight, stainless steel double-wall vacuum construction and an insulated inner cap. Constructed with a sturdy SUS304 stainless steel outer wall and a highly corrosion resistant SUS316 stainless steel inner wall. Comes with anti-slip grooves in the outer cap and a hexagonal-shaped inner cap to allow for easy opening even with gloves on. *The protectors shown in the photos are sold separately.