(I know the files are called switch blade but his is a hidden blade.) Hi! This is the first working switch blade on thingiverse that I know of! Assembly is simple with a string, elastic band and some glue.You will also need straps or string to attach they body to your wrist! THIS SHOULD NOT BE USED AS A WEAPON ITS SIMPLY A PROP!To make, you will need string glue and a rubber band. The rubber band goes at the end of the blade to the body (around the two cylinders) it will only work if the rubber band is small enough. Theres a hole in the blade, put string in and glue it in the hole, feed the string into the crack in the bottom of the blade and through the slanted hole in the body. This need to be long enough to go to your hand and wrap around. Once all this is done glue the cover in the indented hole and attach straps/string to the rectangular holes in the body. Tie the body to your wrist and the string firmly on a finger or around your fingers so it is moderratly firm. when you flick your wrist it should make the blade fly out! When you relax your hand it should go back into place.