Five years – pretty awesome for kids slippers. I’m going to take a picture as my son ADORED them so much that he kept lying that they weren’t small so I didn’t take them away. When he realised I could get a bigger size he let me wrestle them out of his sticky little fingers! Admittedly his feet have grown very slowly and at nearly 11 he still is only just a size 1. They haven’t worn out either, and will also get recycled to friends. Awesome product, I hope you are proud of your invention Dan, you should be.