Descriptions
High quality double wall stainless steel vacuum insulation construction allows the Stainless Mug to keep beverages hot or cold for hours. The tight-fitting flip-open lid with safety lock makes drinking from the mug easy, and prevents beverages from spilling.
- 2-step lid release process prevents excess condensation on the stopper from being flung off while the lid opens
- Tight-fitted flip-open lid keeps beverages hotter or colder
- Safety lock to prevent the lid from opening accidentally
- A special manufacturing technique was used to round the bottle opening, making it smooth and comfortable to the touch when cleaning
- 1-5/8" (4cm) wide mouth opening
- Made of BPA-free plastic and 18/8 stainless steel
- Optional low-profile screw-off lid provides an alternative sipping style to flip-open lid (sold separately)
Specifications
Brand | Zojirushi |
Color | Black |
Heat Retention* | 189°F @ 1 hr. / 160°F @ 6 hrs. |
Cold Retention** | 46°F @ 6 hrs. |
Size |
2-5/8 x 2-7/8 x 9 inches |
Capacity | 16 oz. / 0.48 liter |
Weight (lbs. oz.) | 0.08 |
Country/Region of Origin | Japan |
**Rating is based on water at a starting temperature of 40°F (4°C) at a room temperature of 68°F (20°C)
Zojirushi Stainless Steel Mug (SM-TA48BA)

What is vacuum insulation?
Vacuum means the air between the outer and inner layers of stainless steel has been removed to create a vacuum insulation. It blocks heat from transferring through air.
The vacuum layer does not have to be thick, as the absence of air is what's important and not the amount. Zojirushi's vacuum insulation is as thin as 1mm, keeping the unit compact and lightweight without compromising temperature retention.
How do Zojirushi vacuum mugs and bottles keep drinks hot (or cold)?
Heat loss happens through 3 methods, and Zojirushi vacuum insulated products use the following methods to block them. Drinks stay hot because heat doesn't escape. Drinks stay cold because outside heat can't get in.

Vacuum insulation prevents heat loss through conduction. Since the air– which is a conductor – is removed between the inner and outer layers of stainless steel, heat isn’t transferred.

A thin sheet of aluminum or copper is wrapped around the outer surface of the inner layer to help reflect radiant heat.

And finally, heat transfer through convection is blocked by tightly sealing the lids on each of the products. Most lids have their own air insulation to further reduce heat loss.
Another key feature is the interior finish. There are two types of finishes,SlickSteel® polished stainless steel, and nonstick coated stainless steel.

Our proprietarySlickSteel® is an electrolysis polishing method that makes the 18/8 stainless steel interior highly resistant to corrosion and stains.

Our nonstick surface is a durable coating that resists odor and stains, making cleaning quick and easy. Some models have a double layer of nonstick coating.