The Boot Blankets weigh just under 2.0 pounds. The Muff weighs 0.67 pounds.
No. The Boot Blankets have a water repellant lining. Even when wet, the 300 gram(high loft) insulation still maintains 75% of its insulating quality unlike goosedown which loses all of its insulating quality.
They are not rated as rating only applies to when the feet are moving. This is also true for your regular boots. The Boot Blankets are not intended for walking. We can only say that wearing the Boot Blankets will keep you more comfortable than being without them.
The Boot Blankets and Muff each have two 8-ounce plies of 300 gram (high loft) insulation, the equivalent of a 16-ounce ply. This is more insulation than any other outerwear on the market.

In Average Cold Weather Conditions (20 to 30 degrees F), a heat pack is NOT necessary. Just slip the Boot Blankets over your regular boots after reaching your stand and while your feet are still warm. Do NOT wait until your feet cool down.

In colder conditions, place a heat pack in the toe of the Overboot before you slip it over your regular boot.

In conditions such as snow, or when you wear rubber boots or a rubber boot bottom, you will probably stay more comfortable by removing your regular boot and placing a heat pack in the toe of the Overboot and then slipping the Overboot over the foot while wearing only one or two pairs of woolen socks. (This is what David Blanton, a member of Realtree's Pro Staff, does when he hunts in Canada in temperatures of -20 to -30 degrees C.) Remember that rubber retains cold more so than does leather.

A heat pack works great in the Hanblanket® Muff when you do NOT want to wear gloves or wish only to wear a pair of light-weight gloves.