They arrived quickly and there was no issues getting them plugged in and working. The first pair lost sound after about one week. 5 jack but this is rectified by purchasing a 6. My fault for assuming they were the same & not checking the tags in the store. I purchased these sandals by suggestion from my doctor. These are reasonably priced, are comfortable to wear and they have a sassy attitude if you plug in the lights. Not sure if they are knock offs or they got a bad batch but too late for me to return. The item said what age size, and Ive ordered the age size of my son but it was too small like when he was 1 years old. Each time I go outside for joking they shut down. My grandson loves it