Door Jam CuffsThese door jam cuffs require absolutely no installation. Restraint systems don't get any more portable than this. The box contains two wrist cuffs, totally separate from one another, each connected to a strap that has on the end a sturdy plastic cylinder. You open the door; put the straps over the top of the door with the plastic cylinders on the other side, then close the door again. Then, slip your wrists through the loops and hey presto, an