■ Applications: Measuring soil hardness ■Target users: Civil engineering, construction ■Features: You can calculate hardness by simply pressing the needle vertically on a flat soil surface. ■Specifications: Standard type *Size... 9.1 x 2.0 x 2.0 inches (23 x 5 x 5 cm) *Weight...650 g *Hardness index scale... 0 - 40 mm *1 cm Spring Strength: 17.6 lbs (8 kg) (1.6 inches (40 mm)). *Cone size: 0.7 inches (18 mm) φ x