They do not maintain a constant temperature, but maintain a specified temperature range below the Ambient or Air Temp. so if the air temperature is. Cools to approx. A well designed Cooler. 12v DC car and 230v AC mains.
eBay
TINSOL New 3.5L Electric Lunch Box 90W Portable Food Heater Suitable for Car or Home Leak-proof Lunch Heating Microwave
Aliexpress UK
The Mobicool MQ40W 12 Volt Mains Thermo Electric Cool Box Cooler on Wheels is a sleek and versatile lunch kit perfect for on-the-go use. Its universal design makes it compatible with various items, while the black colour adds a stylish touch. This cooler box keeps food fresh for longer with its thermo electric technology, making it ideal for picnics, camping trips, or any outdoor adventure. Featuring convenient wheels for easy transport, this cooler box is a practical and reliable choice for keeping your food cold while travelling.
eBay
USB Electric Heated Lunch Box Leakproof Outdoor Portable Office School Car 12V 24V 5V Food Warmer Container Stainless Steel Set
Aliexpress UK
14L cool box electric 12V in good condition comes with 12v power cable to plug in the car 12V Collection only WV11 No time wasters plz
eBay
2L Electric Lunch Box 304 Stainless Steel No Water Needed Portable Food Warmer Automatic Heating Meal Container for Office Home
Aliexpress UK
ICELESS THERMOELECTRIC TECHNOLOGY CFC-free thermoelectric technology and brushless fan motor efficiently cools to 40°F (22°C) below surrounding temperature or warms to 140°F (60°C), using less power than your vehicle’s tail light.
eBay
1.2L Capacity USB Rechargeable Portable Wireless Lunch Warmer Box Electric Cordless for Office Travel Car LED Display Type-C
Aliexpress UK
Dellonda Portable Fridge Freezer/Cool Box with LED Display, 36L Capacity. Model No : DL13. FULLY PORTABLE - 36L Portable compressor fridge freezer cool box. Lightweight and compact design with handles allowing you the flexibility to take with you anywhere you go.
eBay
Outdoor Electric Lunch Box for Fishing Camping Portable Rechargeable Food Warmer Cordless Heating Meal Container
Aliexpress UK
15L Portable Compressor Car Fridge Freeze Electric Camping Cool Box 12/24V DC. With the car battery protection system, it works perfectly in your car. Suitable for outdoor activities such as picnics, camping, travelling and so on.
eBay
Outdoor Socket Waterproof Box 86 Outdoor Electric Vehicle Charging Socket Lock Box Lock Anti-theft Electric Waterproof Cover
Aliexpress UK
24L Electric Cool Box Cooler for Drinks Food Ice, Hot & Cold Coolbox for Travel Camping Picnic Caravan Festivals, 12V DC & 240V AC Adapter. Simply plug it into acar lighter socket and let the box keep your food and drink cool.
eBay
80W Electric Heating Lunch Box Bento Travel Food Heater Car Plug Leak Proof Stainless Steel Electric Lunch box
Aliexpress UK
Capacity: 26L. For superior cooling, portable storage and fresh food, this electric cool box is great. Simply plug into a car lighter socket and let the box keep your food and drink cool. Alternatively you can use the 240V UK Mains plug provided with the unit to plug into mains electrics.
eBay
Portable Medicine Box, Medication Dispensing Box, Seven Days A Week, Medication Dispensing Box, Portable Mini Medication Box
Aliexpress UK