What is a good 401k fee?

Good day, I'm curious about the fees associated with a 401k plan. I understand that these fees can vary greatly, but I'm wondering what would be considered a good or reasonable fee for a 401k plan? Are there any specific fees that I should be looking out for or avoiding? Additionally, how can I determine if the fees I'm being charged are fair and in line with industry standards? Thank you for your insights.