These seem to be very sturdy, they are not going move around by using them. I used them at the curb to extend the width of my drive way. I live at the end of a court so the curb has an arc to it so I purchased 4 of these so with a slight gap ( about 1/2 inch ) between each one they worked out perfect. Now when driving my vehicles up and down the curb you don’t even realize there is a curb there.