I have bought dozens of different belts for my students, looking for always the best. For all ranks - every test requires a belt that is a statement of respect for all that work and sweat to get there. The Adidas Black Belt is my favorite student Black Belt. It is supple, strong, ties well, lasts long, has a decent thickness and heft. This is what I use for all Black Belts up to 5th Black. My 6th Degree belt is an Eosin Panther, a great belt, the best, and one I'd recommend for anyone who wears their belt every day for more than 6 hours a day. It takes more than a few months to loosen up enough to tie easily. The Adidas is my favorite belt for that first decade of use, 1st through 4th. A great belt.