A word ( or two )of warning to folks parking on steep sites.
I watched a camper who accidentally left one Balchock on one side of his camper, pull out of a campsite.
The Balchock bent & twisted, instead of jamming the wheels to keep them from moving.
Now I don't know if some other brand of X type chock would have held the wheels, but I doubt it.
I also don't think that having two Balchocks would have made a difference. Or maybe he didn't have them tight enough. Who knows ?
The lesson I took from this is "Don't rely on Balchocks to keep the wheels from moving under serious strain ".
Another time....I watched a commercial boat launcher back down a ramp with a 27' boat on his adjustable trailer.
Once the trailer wheels were in the water, he got out of the truck, put a serious wedge behind the driver side wheels, and maneuvered the trailer controls to begin the launch. That is when the truck started drifting backwards down the ramp.
I watched the drivers side rear wheels climb up over the wedge, and drop down the back side, as the driver scrambled back into the truck and jammed on the brakes.
Crises averted. But the lesson I took from this is Don't rely on a wedge (or two ) to keep your vehicle from moving on a really steep slope.
Balchocks work great on nearly level sites. I use mine every time I set up. First thing put on, last thing I take off. They have never failed to work.
But I would not set up camp on a steep slope. Go somewhere else, or leave the truck attached, in park, e-brake on.