18" Flexible Clamp Adaptor for Multimeters/Clamp-On Meters The Extech CA3018-NIST CAT IV 3000A AC 18' Clamp-on Adaptor expands your meter’s capabilities to measure AC Current. The CA3018 fits most MultiMeters or Clamp Meters with standard shrouded banana plug sockets. Flexible clamp jaw easily wraps around bus bars and cable bundles where standard clamp adaptors and meters can’t. The thin 7.5mm cable diameter easily fits into tight spaces. 18" (45.7cm) clamp cable length. With NIST Calibration.