Its high precision bubble level ensures that you get the most accurate reading every ,The more you use it, the better your putting game will be Efficient Golf Ball Marker: Helps play by quickly and accurately identifying the slope of the green,Works with any type of putter and is suitable for use on any green ,Simply place it behind your ball and read the slope of the green. With practice, you'll be to adjust your putting game and sink more putts Boosting Golfer Confidence: By accurately reading the green, this product can help boost your confidence on the course and improve your overall game. Other golfers will at your accurate green reading and improved putting game.It's the perfect accessory for any golfer looking to improve their putting game Colour:Black Material:Zinc Alloy Package Contents: 1 x Slope Reader Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.