We wanted to remove a rock about 3 feet by 3 feet from the backyard so I bought this kit. We drilled holes off center in a straight line (not to get too ambitious too easily) and placed a series of springs/wedges. We scored each wedge as indicated. they just got stuck. End. One tip was badly bent and we couldn't get most of the wedges out. After that we borrowed a jackhammer which did the job. For us it was money wasted as we do this type of work all the time.