These were supposed to be 3"x72", the size is closer to 2.5"x68". Box of 17 units.

Closed Cell Polyethylene Foam
Meets SATM C1330 Type C
Made without CFCs or HCFCs

PRODUCT DESCRIPTION
Backer rod is a closed cell, resilient, polyethylene backer rod used as a backup material for construction joints and applications that require sealants. It performs as a depth control for most known cold applied sealants. Sealants will not adhere to it; no bond breaker is required.

COMPOSITION AND MATERIALS
Backer Rod is a round, black, resilient, extruded closed cell polyethylene backer rod with a water resistant outer skin. It is compatible with most known cold applied sealants such as urethane, silicone, acrylic, butyl, polysulfides, latex, and chinking sealants.

SPECIFIC USES INCLUDE

Expansion joints
Highway joints
Glazing
Log home chinking
Parking Decks

LIMITATIONS

Backer Rod should be installed with a roller or blunt, flat-sided tool. Please follow sealant manufacturer specifications for recommended sealant width and depth ratio. For best results, do not puncture, fold or overly stretch the product. The product is made with a water-resistant outer skin, therefore where moisture resistance is important, care should be taken not to puncture this outer surface skin.

Backer Rod is chemically inert and will resist gasoline, oil, and most solvents. Product will not stain or adhere to sealants.

Density: 1.3-1.9 lbs/ft3

Water Absorption: less than 0.5% by volume

< 0.03 grams/cc

Temperature range: -90F to 190F

Compression Recovery: > 90%

Compression Deflection: 5 psi

Tensile Strength: > 29 psi

Meets standards ASTM D5249 type 3 and ASTM C1330 type C