Here is a
video demonstion with a neat soundtrack.
I am considering an S2+, and I have been told that Convoy's drivers are now constant current, and possibly include current regulation. But I have no first hand experience with a Convoy light yet.
I have bought from BangGood, it was a few years ago before their updated website appeared. I can no longer use the website. The mobile version is completely unusable, and I can't find any way to get it to serve desktop webpages. My only modern browser is mobile Safari on iPad. Site detects my browser, and will stubbornly only serve mobile pages, even if I use mobile Safari's function to request desktop pages. My desktop browser, Chrome on Snow Leopard, is ancient, and won't even load the site. After the lawyers, it will be the OCD web developers against the wall. Bleeding edge web sucks and breaks the Internet. Funny how we were forced to deal with old outdated standards for over a decade, and now every couple of years standards upgrades just breaks stuff, leaving many if not most that don't or can't upgrade to bleeding edge operating system versions, and the browsers that only work on the most updated OS, in the cold. I am pretty sure, initially at least, Steve Jobs is mostly to blame for this. The release of the original iPhone and mobile Safari was astoundingly influential to the state of the WWW.