The Hyde 43660 caulk aid is a multi-purpose caulking tool, it lets you refresh old caulk with a single tool and a minimum of effort. On one end are sharp, high-impact plastic blades designed to shave old caulk clean from tile or window mullions. A sharp-point (hidden in the middle) removes any remaining caulk from crevices. Once the surface is clean, the padded end of the tool will smooth a new caulk bead to a neat, consistent profile. Also helpful a caulk tube cutter on the back of the tool slices open the replacement caulk tube.