Compatible with most water filter housings which accept 4.5 inch width filter cartridges (Wide Body) This wrench is compatible with many model water filters that require a "wide body" water filter cartridge. The actual inside diameter dimension of the wrench is 6 1/8" wide. Additional Details ------------------------------ Bullet point: UNIVERSAL COMPATIBILITY: This water filter wrench is specifically designed to fit most 4.5-inch width (wide body) filter cartridges, making it an essential tool for homeowners and professionals alike. Whether you?re maintaining a water filter system or a smaller filtration unit, this water filter wrench ensures a secure fit for a variety of models. Our water filter housing wrench is engineered for effortless compatibility providing a reliable solution for your filtration needs. Product description: Compatible with most water filter housings which accept 4.5 inch width filter cartridges (Wide Body) This wrench is compatible with many model water filters that require a "wide body" water filter cartridge. The actual inside diameter dimension of the wrench is 6 1/8" wide.