The Mack Replacement Pipe is a practical solution for replacing the Mack Part # 4ME-21783P4. Designed to fit most MR Mack makes and models, this replacement pipe offers convenience and reliability. Sold individually, it provides an efficient and cost-effective option for replacing worn-out parts. With its straightforward features and compatibility, the Mack Replacement Pipe is a reliable choice for maintaining the functionality of your Mack vehicle.