MAXTRAX Mounting Pins are the easiest, safest, and most-secure way to mount your genuine MAXTRAX Recovery Boards. Because of the unique design of our patented Keyhole, our Mounting Pins (both 40mm and 17mm) can carry either one or two sets of MAXTRAX (two or four boards) and their M10 stainless bolt has a provision for a small padlock, like the MAXTRAX MAXLOX.
 
Two individual rotating Nylon “keys” allow you to securely restrain your MAXTRAX while the primary component remains stationary, attached to your roof or bed rack, or custom mounting application.
 
Sold in a set of four, enough to mount one or two sets of MAXTRAX (two or four boards total). 
40mm and 17mm refers to the length of bolt used to mount the pins- both the 40mm and 17mm pins will hold either one or two sets of MAXTRAX.