Specifications:
Colour: Black
Voltage: 3.7 V
Size: about 23cm x 28cm x 9.4cm
Material: Cotton+Spandex
Heated Area: Front instep
Battery: 2 x 3.7V rechargeable li-ion batteries
Heat Setting: 3 Levels Temperature Setting- High (Red), medium (Orange) and Low (Green).
Temperature switch and lasting hours(Fully charged):
Red: 5 Hours
Orange: 7 Hours
Green: 9 Hours

Features: 
-Brushed soft comfort for feet,elasticity.
-Manual control of temperature: High,Middle,Low.
-The socks are free size, great for men and women.
-The socks with box can be as a best warm heart gift for Family,Parents,Friend in Cold Weather.
-Perfect indoor warm feet gear for cold weather. Also great for outdoor athletic activities-outdoor trail.

Package included:
1 pair x Socks
2 pc x 3.7V li-ion batteries
1 pc x AC Charger
1 pc x Packing box

Notes:
1. Do not use a household power source to heat it directly!
2. Manual measuring, please allow 1 ~ 3cm error,thank you.
3. Due to the difference between different monitors, the picture may not reflect the actual color of the item.