Hello, To restore a bit this product and for those who do not know how to use! For as to turn off, you must press 3 seconds on the timer button start / stop on / off !!! For those who want to do more than 399 images, just do not go to many image and it will trigger "at vitam æternam" the life of your battery or rather the battery life of your DSLR before that Lachera !! For the production made in china, so find something that today is not made wholly or partly in China and I'll show you a liar! For information you will find on the site "Phottix / technical support and download / Phottix TR90" summary translations to use in English, Italian, French and Chinese! That all said, and not yet a point, it also works with a Canon 100D.