Multi-Function Compatibility: Designed to work seamlessly withfor RJ45, RJ11, RJ12, CAT5, CAT5e, CAT6, and UTP cables, this tester is perfect for both phone and LAN wire testing. Quick & Accurate Testing: Instantly checks network cables for various faults including Straight, Opens, Shorts, Crossover, Split Pairs, and Reversals, making it an essential tool for diagnosing crimping errors efficiently.