The National Oil Seals 370065A Trailer Axle Seal is a high-quality seal designed specifically for National brand trailers. This seal is compatible with trailer axle sizes ranging from 40K to 44K lbs, providing reliable protection against leaks and ensuring smooth operation. As a trusted brand in the heavy equipment parts and accessories industry, National oil seals are known for their durability and performance, making this seal a practical choice for maintaining your trailer's efficiency.