The TESCO Test Switch Adapters (Cat. 290-13T / 290-8T / 290-6T4S / 290-6T3S) enable the safe testingof transformer-rated meter sites without installed test switches. TESCO’s Test Switch Adapters work by plugging into a meter socket and providing a test switch interface. Designed as a convenient, portable accessory for the TESCO 6330 Meter Site Analyzer, the Test Switch Adapters come in several versions to test  different terminal configurations: 290-13T, the 290-8T, the 290-6T4S, and the 290-6T3S.