I somehow missed out on the world of stretchy belts. It never occurred to me that the miracle that is 2 and 4-way stretch pants would also exist in a belt form.
Yaak is a company in New Mexico that makes exactly two belts - the M series and B series belts. Both come in black (the best color) and with a band that has a 10% stretch. Arcade is probably more well known as a stretch belt maker.
I recently purchased both of these and have been wearing them every day. I LOVE stretchy belts! These are more suited for casual use and wearing as an every day belt but they are simple in black and could be dressed up.
It's hard to describe what makes a stretch belt so great, so you'll have to trust me. The belts are exact in fit and make transitioning to standing and sitting very easy and comfortable. That 10% stretch is really nice.
The B series belt is made of a carbon fiber composite hook and is great for travel as there is no metal to set off a metal detector. The M series belt has a cool magnetic buckle that's very satisfying to use. This video explains.
Both belts are adjustable, and you cut them to length (or leave as is).
I purchased both with the Performance Stretch II in Black.