It has a spot for keys underneath just like the engine pro. and also a key to pull the battery, but youre always better off using a lock since anyone could roll it away.
Its a little confusing on their website, but mine is the Engine pro, there is also an EP-2 but that seems to have less Watts and range. but they may put out newer models soon I think the newest stuff is adding 2.0 to the description.
I like the x20 more. Having the extra battery pack feels like a spare gas tank. It makes a convenient time to switch on for the ride home. I also think the x20 is more quiet to ride.