Impossible Lock (Version 2)
This is pretty novel, a padlock without a key or combination, the impossible lock (probably a bit of a lie as it can be opened).
This chunky padlock, made from brass and stainless steel, weighs 400 grams. The brass part of the padlock is 42mm high and 55mm wide. The entire padlock, including the hasp and the rod at the bottom, is 203mm high.
There are 5 steps needed to open it. There is no key involved.
Without the instructions, very, very difficult.
The Impossible Lock 2 is available for Grand Illusions at £118 (~$200 ouch).