... 25cm, 30cm, 35cm, 40cm ApplicationIt is applied to investigate tress growth. Through drilling tree core samples, without destruction of trees normal ... growth, it can identify trees growth rate, age of the trees, trees growth hardness degree and nutrients migration.CharacteristicAdopt international ... extractor: d=5mmDrill pipe length: 20cm, 25cm, 30cm, 35cm, 40cm Plant Growth Awl