This is a mostly functional replacement keyfob for a Lotus Elise or Exige. To use it, you have to get a copy of your key made on a key that is all metal without the plastic handle, then, with a hacksaw, cut the key to fit into the slot in the new keyfob. Transfer the electronics from the original keyfob to the new casing. Note: The casing is not watertight, nor does it snap together, so you need to either glue it together (then, changing the battery becomes a problem, but you can pry it apart with pliers and destroy it and then just print out another one) or tape it together.I have had the thing fall apart in my pocket one time, and it esp. needs something to hold it together when twisting it (e.g. as when you turn the ignition on.)This thing isn't even close to perfect, but, it's alright. Feel free to make improvements. The canonical OpenSCAD source is here:https://github.com/smcameron/buzzbomb-keyfobLicense is GPL v2 or later. Feel free to send me patches.Print it out, transfer electronics from old keyfob, Make a copy of your key on an all-metal key. Hacksaw new key to fit into new casing. Tape or glue casing together.