SLM model 4 601-010-1000 model 4601....the good one. It is clean outside and has been tested with hybrid b 2.3 power supply. This one will do near 100mw but I didn't want to push it. It has a good stable state near 23mw. I would like to know if anyone would like to provide it a good home. PM me if you are interested. This is for the head only.