This straight Raychem tube is preformed to create a 90 degree boot when it is heated. It has a reinforced lip to help grip the connector snugly. It tapers to a smaller diameter and thinner wall at the opposite end to gracefully transition to the harness.
These tough Raychem boots are a motorsports staple due to their excellent material properties. They are rated to:
Withstand 168 hours at 320 degrees F but still not crack when bent at -100 degrees F
Soak for 24 hours in hot gasoline and still have 80% of its original strength
Continuous fuel immersion requires a part like 222K142-12-0. This material can withstand continuous immersion.