I've known "Kooniu" somewhat distantly for years on a number of whip-centric internet forums; Club Obi-Wan's bullwhip forum, The Whip Basics forums, Facebook groups, etc. etc. etc. and as long as I can remember, he's been sharing the results of constant tinkering with new designs of flexible weapons for fast deployment; whip belts, his own version of the intimidating Urumi steel whips of Indian martial arts, etc. etc. One of my favorites he shared many moons ago was a "Universal Whip" That had a removable/replaceable handle that could quickly convert between being a bullwhip, a stockwhip, and a snake whip, (for definitions of these three types of Supersonic Whip, read here.)
Andrzej visited my website a couple years ago, read some of my experiences, and found we had a lot in common in terms of philosophy of whip-based martial arts. I however tend to be a bit more internally focused...almost meditative in my whip practices. Andrzej is much more focused on application, and is focused on where the rubber meets the road. Kooniu is a very "Do it Yourself" kinda fellow, and is constantly developing new variations of those self-made whips, throwing on some padding and a mask and "Field Testing" them with fellow martial artists, and then going BACK to the workbench to fix the problems he's found in his designs. You can find more about that at his website.
His personal style, dubbed "The Vagrant Whip" utilizes a lot of spontaneous flow and requires a lot of speed and skill. The whips Kooniu prefers have somewhat longer handles than the whips I use, which makes carrying them around a bit complicated. Hence this design. I'll just shut up and post the video now.