5mm into it. Over the 2 or 3 years they last (maybe with a hint of a toe poking through towards the end) they dont work out too expensive per month. They size it these slippers in size pairs, 7-8, 9-10, 11-12. Firstly, to achieve any bass with IEMs you MUST, repeat MUST, get a good connection inside the ear. This book will not be for everybody. In my review I marked the sizing as fit smaller. I just got these today and I wanted some decent earbuds that didnt break the bank. Just got these today and these are super lightweight- just like my adidas cloudfoam. I have owned a few different types and these rank among the top. Brought this for my daughter for university.