As its name suggests, these pigtails are only for indoor use and unsuitable for harsh environments. A fiber optic pigtail is a short length of optical fiber —typically 0. The connector end is polished and tested under factory conditions, ensuring low insertion loss and high return loss. The Waterproof fiber. Since fiber optic cable carries no electricity, we don't worry about electrocution. Similarly, we don't think about personal or property damage due to fire because it isn't a source of heat Understanding the safety hazards that go with fiber optic cable is critical for those who install or maintain. Executive Summary: A fiber optic pigtail is one of the most commonly specified yet least understood components in structured cabling.