Description:The putting tutor has two marbles at its front edge, which tell you whether or not youve just made a pure strike and started a putt on line. If your putt dislodges a marble, it means your ball started offline. This is good feedback because: you cannot learn how much a putt breaks if you hit it poorly, you need to know which of your strokes start putts on line vs. Off line, youll learn to consistently groove a reliable purestroke putting stroke,Different marble Gate positions (standard, Pro and super Pro) greenreading help: learn how much putts break simply by adjusting the aim of the putting tutor higher or lower, until well struck putts go in.Features:Teaches online putting Improves greenreadingSquares putter face to aimlineImproves stroke mechanicsColour: BlackMaterial: hightech composite materialSize: about 136.522cm5.122.568.66inchWeight: about 300gList:1golf putting tools: board body, steel ball six, zipper case