Designed to fit perfectly to 10-inch or 20-inch long Big Blue (BB) housings to replace 4.5-inch dia filter cartridges
The inner diameter of the wrench is 5-7/8 inch between shortest points and 6-3/4 inch between longest edges
Compatible with most of the Big Blue type water filter housings that accept 4.5 inch dia water filter cartridges
Durable, strong plastic material
Full circle design with 4 teeth for grip