I am a machinist on my feet 8 to 12 hours a day 6-7 days a week on cement floors. I have tried other boots but nothing comes close to these. They are comfortable from day one,no breaking in time. After two years, I replace them due to the inside of shoe finally breaks down. Outside of shoe still functional. Just purchased my fourth pair in 8 years. Thanks Proline for a great work boot. Will be purchasing my 5th pair in two years. Highly recommended.