Autonerdz forums

It has been sometime since I posted here. I will re-introduce myself. I am medically retired, bought a 4423 from Tom Roberts when he was here. I was a tech of sorts; serving on fishing vessels as their engineer from time to time, worked in auto repair shops several times for a very short percentage of my career and did maintenance and repair on company vehicles at the boat repair facility I worked at for thirty years. I took an interest in the workings of internal combustion engines, refrigeration and the electrical and have knowledge and qualifications from study such but not so much practical repair experience, mostly maintenance. What is a KG file?

Thank you, Trevor.