Female Socket: 20AMP (for Nema 5‑20P to 5‑20R) extension cable. Female socket is 15Amp and 20Amp combs. Has more flexible and stable performance. Feature: 1. Pull Resistant: For Nema 5‑20P to 5‑20R cable is one piece molding and reinforced design to ensure that it will not fall off during use, and it is more durable against pull.