Pants Talk! To Keep your kids safe from abuse. How you talk about it ?

To help my child understand I ordered Pants Talk Kit from NSPCC. Visual aids really helped my children fully understand what is all about. It worked on my toddler as well as my older child. Before that I didn't even know where to start. It's difficult subject but has to be covered. I wanted my kids to be safe and have happy childhood. I know you may think that it is not for you, no parent ever wants to think their child could be affected by sexual abuse. PANTS never mentioned sex and explain your children by using simple child friendly language to make sure they stay safe. But I am curious how do you do the talk? Do you think it's important? What age you talked to your kids?