The golf training aid is made from premium elastomer and translucent polycarbonate. The tool is elastic, so the ball usually returns to you on your misses. You don't have to own too many golf balls.It rolls offside if you putt a golf ball off the trail, while it returns if you putt with good line and bad speed. For more challenging putt, just open micro target and golf ball will stay in the hole if you putt with perfect speed and line. The golf practice equipment gives you immediate feedback according to the quality of your strike.