They were built buy Recreative Industries which was located on depot street in Buffalo close to the William St Post office. They are chain drive to sprockets mounted on axles. The transmission is serviceable although very reliable. It utilized a set of brake bands which brake one side of the transmission which transfers 100% power to the other side for turning. Same is true when shifted in reverse. The tracks make these unstoppable in the snow and they float on top. I worked there for several years first in assembly then as an engineer. Happy to answer any questions i can. Sent from my iPhone using Lake Ontario United mobile app