WHAT IS A GRAVITY KNIFE
WHAT IS A GRAVITY KNIFE I found a great article on noblie.eu that explains what a gravity knife is and its history. According to the article, a gravity knife is a type of knife that uses gravity to open the blade. The blade is concealed within the handle until you let it drop out. Gravity knives were originally designed for military use and were used by soldiers to cut themselves free from their parachutes and handle utility work and even self-defense.