SparkFun COM-10234 Piezo Igniter
This piezo igniter can be used for all sorts of applications where you need a spark to make fun things happen. With a large red button, easy mounting, and a long detachable ignition cable, this would be a perfect fit for your next spud cannon, rocket launcher, or flamethrower.
The igniter itself is about 3.5″ long, with a 0.65″ diameter barrel (for mounting). The cable is just over 2 feet in length.