This product is a rear cylinder base gasket for Harley-Davidson motorcycles from the years 1963 to 1983. Manufactured in the United States, this new old stock (NOS) gasket is designed for the front placement on the vehicle. The part number 16777-63 is an original equipment manufacturer (OEM) part for Harley-Davidson, ensuring high quality and authenticity. Perfect for restoring or maintaining classic Harley-Davidson bikes, this gasket provides a secure seal for the rear cylinder base.