This Gauge Rake is for use in applying decorative concrete âtoppingsâ, self-leveling/high performance floor coating materials and underlayments in the floor-covering markets. This gauge rake is comprised of an aluminum frame. Just add a handle and choose your cam size. When one contact point becomes worn, simply loosen the wing nut and choose another contact point. A radial edge design maintains uniform coating thickness at varying handle angles and lengths. CAM sets come in a variety of depth settings which makes this a perfect tool for all your overlayment or concrete coating needs.