1/2" Drive Ratchet and Hex Socket

Every Plummet Vertical Haulage systems hitch attachment  a uses M16 cap screws and is supplied with an allen Key in the built kit. 
 
This significantly reduces slop and acts as a safety feature as would be bike rack thieves are unlikely to be carrying a large allen key with them. 
 
If you want to turbo boost your rack install on and off the car purchase this high quality 1/2" drive ratchet and hex socket.