Fluke bht190 adaptor for industrial bus connections for fluke 220 series fluke fluke bht190 p this fluke bht190 adaptor set is suitable for the most common industrial connection systems m12 db 9 and rj 45 each plate acts as a straight through connection for the cable under test and enables access to the individual wires and terminals in order to attach the test probes p fluke bht190 adaptor for industrial bus connections for 220 series