Mirra 88 Shower Control
The Mira controls are both 20 or so years old in both showers, and about ten years ago, I bought one of their service kits and changed the seals and other bits. A few months ago, the control knob started getting stiffer, so I decided to use the service kit again.
Fortunately, I found a Youtube video and the mumbling plumber said do not use the black grease supplied as it is useless, but use silicon grease as it is safe and long lasting. Smothered everything with it, and the control is as smooth as a baby's bottom. And precise control.
Just thought you would lke to know......if you are contemplating servicing your shower control