A pivoting lifting device. The heavier the object it is lifting the greater the pressure holding it. Just tie a loop of rope or a chain to the top holes and lift...Show more away! Print two of everything and four each of both PinA and PinB. They just push together. You could use bolts instead of the pins as well. The foot needs support in the holes to print the inner wall flat. If the feet don't line up correctly then it is on backwards. The holes on the foot are closer to the edge on the ribbed side of the Lower Arm. Happy lifting!