The BK Mueller and ProLine 8" overall length stem is for the 4" faucet. The BK Mueller 888-554 8" Overall Length Stem is a high-quality replacement part designed for BK Mueller faucets. This 8-inch stem plays a crucial role in controlling the water flow in your faucet system. It’s made from durable materials to ensure longevity and reliable performance. The BK Mueller 888-554 8" OAL Stem is easy to install and is designed to fit perfectly with specific models of BK Mueller faucets. Please check the compatibility with your faucet model before purchasing. This stem is an excellent choice if you’re looking to maintain the performance of your BK Mueller faucet system.