Caulk Backer Rod, 20-Ft. x 3/8-In.
SKU: 6289227
3/8" x 20', Caulk Backer Rod, For Gaps & Joints, Non-Absorbant, Closed Cell Polyethylene, Pre-Caulking Material, Use Before Caulking To Fill Gaps & Openings Larger Than 12" x 12", Prevents 3 Point Bonding.