Sika - Polyethylene Foam - Closed Cell Backer Rod (Gray) - to Fill Joints and Cracks Before applying sealant - Water-Resistant, Flexible - 3/4" Diameter x 20' ft. Long

This is the perfect size for ear posting. I premeasure and cut about 6" pieces. The only thing I don't like is that it's packaged in a coil, so the pieces end up in a curve. You have to reshape the piece and then tape it before posting your Doberman's ears. They are lightweight and durable.

did the job

Required if the cracks or separations in the concrete go all the way through. If you don’t use it the self leveling filler will drain through the separating surfaces and will be lost.

It's basically dense styrofoam with great elasticity that allows you to squeeze it into cracks. It works well as intended. It doesn't rip off easily, which is what you want.

We had an expansion joint that needed to be replaced. Whatever was used previously disintegrated and had to be removed. The gap (over 1/2 inch) was cleaned thoroughly and ready to be filled. The backer rod was easy to use. I slowly pushed it between the gap so there's a snug fit. Afterward, I squeezed self leveling sealant and it flowed smoothly across the gap.No issues with the backer rod. Just make sure it's not punctured while pushing it into the gap.

Very good quality for stopping air flow around doors and windowes.

Good backer rod. Closed cell and dense. The correct diameter. Seems very well made. Buy and use with confidence.

Squeezes into expansion joint that was 1/2 inch nicely.Since this joint was deep I also put some sand in first.Then the foam backer installed nice and snug.Then the self leveling caulk joint filler, worked great.