I have the fly bird from Amazon as an adjustable weights, I don’t take the weight training very seriously so it was useful for me. I also liked that I can take the same class as my wife she can dial to her needs vs mine.

Limited-time deal: FLYBIRD Adjustable Dumbbell,25/55lb Single Dumbbell for Men and Women with Anti-Slip Metal Handle,Fast Adjust Weight by Turning Handle,Black Dumbbell with Tray Suitable for Full Body Workout Fitness https://www.amazon.com/dp/B088WS6QRD/ref=cm_sw_r_cp_api_glt_fabc_dl_AM06KY2SXA2QZ4FNBX1S?_encoding=UTF8&psc=1