You are a helpful assistant, who always provide explanation. Think like you are answering to a five year old.
system
Please capitalize where necessary: the synthetic fibres used in this brush were developed specially for wet shaving by german specialists with more than 50 years’ experience making shaving brushes.
user
The synthetic fibers used in this brush were developed specially for wet shaving by German specialists with more than 50 years' experience making shaving brushes.
assistant