I see that the D185 has now become the D185 Mark II, what changes have been made to the instrument?

The new D185 Mark II now incorporates a number of enhancements which have been added in response to user feedback. The front panel now includes a polarity reversal switch, a multi-turn control dial for setting the output voltage and rear panel switches to alter the trigger settings. This latter feature means that the stimulator can be set up with different EP systems without having to open the case and make internal adjustments. Finally, the new model includes special circuitry to reduce stray mains (line) frequency pickup below perceptible levels.