These lock into place easily, comes shipped with four squares together for a 24 x 24 size fit which worked out for my project to place on top of a straight path of concrete floors in a room that gets wet daily. I didnt see how undoing them would be easy, so just know what you want to do before snapping them into place, which I did by just stepping on the tile. I also place interlocking foam mats on top to cushion feet and they dont slip as long as you have the ridge side down, soft part on top. I liked these so I bought another set.