Best Seller | HUMBOLDT HC-2938 Concrete Corner Crack Monitor Concrete Crack Monitor, Color Clear, Graduation Color Black/Red, Graduation Marks 0 mm, Graduation Units Millimeters, Highest Horizontal Measurement 25 mm, Highest Vertical Measurement 10 mm, Includes Record Sheet, Lowest Horizontal Measurement -25 mm,... ... more HUMBOLDT HC-2938 Concrete Corner Crack Monitor Concrete Crack Monitor, Color Clear, Graduation Color Black/Red, Graduation Marks 0 mm, Graduation Units Millimeters, Highest Horizontal Measurement 25 mm, Highest Vertical Measurement 10 mm, Includes Record Sheet, Lowest Horizontal Measurement -25 mm,... | | $100.99 go to store |