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American Plumber, Culligan, Pentek OR-100 O-Ring for Big Blue Housings

Price $4.99 List Price Price $9.99 Save 50%
Availability: In Stock
Choose a quantity
  • 1Filter$4.99 
  • 3Filters Price $4.59 each
  • 6Filters Price $4.19 each
  • The OR-100 rubber gasket is 5.75-inch outside diameter and is a Buna-N FDA grade o-ring
  • The OR-100 O-Ring gasket is used to seal the housing sump to the housing cap to prevent leaks
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The OR-100 o-ring is a lubricated rubber gasket for Big Blue whole house housings. The OR-100 is NOT for Big Clear housings. The OR-100 O-Ring has been branded under Ace Hardware, American Plumber, Ametek, Culligan, Pentek, and USFilter Plymouth Products. The OR-100 o-ring should be replaced every two filter changes or if there is damage to the OR-100 oring. The Pentek OR-100 o-ring gasket should be well lubricated with silicone lubricant to prevent leaks in the water filtration system.
Package Qty1
Used In BrandsPentek, Tier1
Manufacturer's IdOR-100
Actual Size (in)5 1/2 inches (inside diameter) x 5 3/4 inches (outside diameter) x 3/16 inches (width)
Actual Size (cm)13.97 x 14.605 x 0.47625
Warranty GuaranteeUnconditional Product Guarantee for Life of the Product

Reduced Contaminants

The TIER1-OR-100 is comparable with the following part numbers


The TIER1-OR-100 fits the following model numbers



  1. The OR-100 o-ring is perfectly doubled up in the package so the o-ring looks too small for your housing at first glance
  2. Once you take it out of the package, you will see the OR-100 o-ring is the correct size for the Big Blue housings