CRACKMON SCRATCHMARK Crack Monitor Kit for Reinforced Concrete and Masonry Permanently records absolute crack movement along X-Y axes over 34mm diameter range Engineered and manufactured in the USA from high-grade spring steel Nickel plating improves corrosion resistance for outdoor use Patented solution uses low-cost Scratch-a-Track crack monitoring consumables (sold separately) Use stand-alone or in conjunction with CRACKMON 2D and 3D Crack Monitors