MRC Controlmaster 20 - 2 versions?

Hi, I need some help here, and appreciate whatever you can contribute…

I own 3 MRC Controlmaster 20 units - all recently purchased. Two are stainless cases with exhaust fans, the third is a black case without an exhaust fan. I have learned from MRC that the black unit is the new version, while the stainless are the older versions. Frankly it would seem to be the other way around. My questions are:

  • Other than the exhaust fan is there any difference?
  • Is there anything “wrong” with the older version with the fan?
  • When was the stainless version actually produced?
  • The handheld units are not interchangeable. Why was this done?

Thank you all for your help,
Mobilman44

Hi, I need some help here, and appreciate whatever you can contribute…

I own 3 MRC Controlmaster 20 units - all recently purchased. Two are stainless cases with exhaust fans, the third is a black case without an exhaust fan. I have learned from MRC that the black unit is the new version, while the stainless are the older versions. Frankly it would seem to be the other way around. My questions are:

  • Other than the exhaust fan is there any difference?
  • Is there anything “wrong” with the older version with the fan?
  • When was the stainless version actually produced?
  • The handheld units are not interchangeable. Why was this done?

Thank you all for your help,
Mobilman44