M-D Building Products 71506 Backer Rod For Gaps and Joints, 5/8-by-20 Feet, Gray Poly Foam Caulk Saver acts as a filler in large gaps before applying caulk. Insulates and cushions. Use in pavement cracks, wall joints and foundations.

• The product is 5/8"x20' Caulk Back Rod
• Easy to use
• The product is manufactured in China
• Provides a sound surface for caulking projects
• Fills large gaps and openings to prevent drafts
• Recommended for use in expansion joints in driveways and sidewalks
• Twist multiple strands of cord together for extra large gaps; easily trimmed to size with scissors