With 3.44" (9 cm) actual size this o-ring is designed to fit standard 2.5" filter housing. Use with: Whole House Sediment Filter (AO-WH-PRE or AO-WH-PREV). Keep the water-tight seal on your whole house sediment filter. Use only certified, genuine A. O. Smith replacement filters for continued contaminant removal and system performance. Replacements made easy - use when you change out your filter every 3-6 months. Includes 2-pack o-rings. Upgrade your whole house water filtration system with our genuine AO Smith AO-WH-STD-OR-2 O-Rings. This 2-pack set features 3.44-inch (9 cm) o-rings, designed to fit standard 2.5-inch filter housings, ensuring a perfect water-tight seal. Crafted from durable black rubber, these o-rings are built to last, providing a seamless replacement for your sediment filter every 3-6 months. Compatible with AO Smith's Whole House Sediment Filters (AO-WH-PRE or AO-WH-PREV), these o-rings maintain your system's performance and contaminant removal efficiency. Keep your water clean and your system running smoothly with these certified, genuine AO Smith replacement o-rings.