Beadlock wheels lock the out side of the tire to the rim with grade 8 bolts instead of the air pressure and a lip that holds tires to conventional rims. Beadlock rims are basically a two piece rim (the wheel and the lock ring) that sandwich the tire between the two pieces of rim. This allows you to run very low air pressure to increase traction (1-7 PSI) with out risk of de-beading or popping the tire off the rim. Most beadlock companies lock the outside edge because with the way force is applied to the tire during rock crawling the outside bead is 90% more likely to come off the wheel then the inside bead, but some companies will lock the other side if you so wish it.