Scratch-a-Track Crack Monitor Refills (10-Pack + Case) for Buildera CRACKMON ScratchMark Crack Motion Monitor</br></br><div style="text-align:left"><b>[Product Information]</b><br><ul><li>Permanently records absolute crack movement along X-Y axes over 34 mm diameter range</li><li>Engineered and manufactured in the USA from high-grade thermoplastic</li><li>Specially formulated tracker coating resists weathering for lasting permanence</li><li>Patented solution uses low-cost Scratch-a-Track crack monitoring consumables</li><li>For use with Buildera ScratchMark Crack Motion Monitors (sold separately)</li></ul></div></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br></br><img src='http://ecx.images-amazon.com/images/I/519OOw5aBnL.jpg' noproxy></br><img src='http://ecx.images-amazon.com/images/I/41FuL7YkgJL.jpg' noproxy></br>