Bed boots keep your feet warm inside sleeping bag, or in your bed. The strap tightens around the ankle to help keep it on.
The overshoe is made from cordura with the waterproofing on the bottom of the sole. They just slip on and off and help protect the sole of the boots. The boot itself is quite slippery, thus the overshoe for walking around the house or even out on the snow.
Boots are in black or emerald green. Overshoes are black, grey, royal or forest.