Fluke EI-162BN Split Core Transformer. A680506211, 12.7 inch (320 MM). Mfg. part Fluke 2577159. Fluke parts and accessories. Used as a Selective clamp for ground loop resistance measurement around power pylons. Inner diameter of the clamp is 320 mm (12.6 in). Includes the split core transformer. This Split Core Transformer can be used in conjunction with the 1625 Kit or the 1623 Kit.