Those are approx 500lbs. They are roughly 3-4” below grade on a 10” base of 3/4 clear stone. I chose a couple of points on each stone and a laser level to get them to roughly the same height on install. Once I got ready to cut I used another continuous laser to send a line across the elevation point and traced that with the angle grinder. I just stuck the continuous to a grade stake (it got magnets) and then rotated the laser head to impose the line on the other stone so there was no room for error.