Images from the ‘circuit breakers (CB's) you see often colored caps or kraagjes around the CB's. They usually have a red color, and sometimes yellow or green caps.

This caps around the CB's are in the ‘environment’ also ‘chicken rings’ ...

When there is an electrical or mechanical failure and need to quickly get to the correct CB to be sought, then it is often a whole quest to find the right one.

This ‘Circuit breaker button caps’, you can add it to the CB's in your homecockpit. At least for those who the CB panels have been installed ...

You can put them in the market to buy but are not cheap (€3 per piece for a plastic ring).

I have a number of caps itself patched together from the caps of bottles of water from Aldi.

The necessary explanation with pictures can be found on following link : http://www.flightdeck737.be/hardware/platform/aft-flight-deck/circuit-brackers/