The Engine Crankshaft Seal Kit Rear by Fel-Pro, model BS 40509, is designed for use on the rear portion of a vehicle's engine. This kit includes a crankshaft seal to help prevent oil leaks and maintain proper lubrication within the engine. Fel-Pro is a reputable brand known for producing high-quality gaskets and seals for engines, ensuring durability and reliability. This kit is essential for maintaining the optimal performance of the engine and preventing any potential damage from oil leaks.