5 C with bloch 5. I use earplugs when I swim with my Tayogo Force, so this is not new to me. Be difficult to get a good fit unless you ordered at least three pair to try on. BUY IT ???? Once you get the straps adjusted just right for your feet, these are very comfortable and durable sandals. When i measured them against the Annadel Eirwyn wedges purchased from Amazon last year i noticed they were a full half inch narrower but were marked 9. My husband wanted a back strap on his new sandals as he retires his 10 year old/worn out/unrepairable Tatami slip-ons. These earbuds are literally the only ones I found that could be used for lap swimming and can store music as well. - The 20? USB-C charging cord is the new standard that?s smaller, carries higher voltage or data speed, and best of all is reversible (there?s no wrong way to insert it). With these, a/v sync is spot on.