Covert Mercenary Ninja Mini Kubaton Keychain Spike Set. This is not your ordinary keychain it has a hidden compartment that houses four Ninja spikes. The steel mini baton has a black finish that has ridges that conceals where the top and bottom pieces screw together. Inside there are four black steel spikes that are 4 inches in length and are very sharp. Overall Length with Key ring is 6.25 Inches.