M-D Gray Polyethylene Caulk Backer Rod For Driveways and Sidewalks 20 ft. L X 5/8 in. T

The MD Building Products 5/8 in. x 20 ft. Gray caulk backer rod for gaps and joints acts as a filler in large gaps before applying caulk. It insulates as well as cushions. Use in pavement cracks, wall joints and foundations. Backer rod is easily trimmed to size with scissors.
Non-absorbent, closed-cell polyethylene pre-caulking material
Easily trimmed to size with scissors
Twist multiple strands of cord together for extra large gaps