You may have up to three options.

BBM - If you are very comfortable breaking down your bike when disassembling and packing it. You will have to remove both wheels plus many other components like bars/stem, pedals, rear derailleur, rotors, seat and seat post. An advantage to this box is it gives you the best rates because it’s the smallest option for full-size bikes. This also saves you money when shipping internationally.

BBL - With this easy-to-pack option, your rear wheel stays on. You do still have to remove some other components but not as many as for the BBM. It ships well domestically and internationally.

BBXL - With this easy-to-pack option, you remove both wheels, but you can leave most road/gravel bars on. Often, you can even leave your aerobars on! This is a great option if you want to keep your bars and stem in place while shipping. It’s also great if you have an integrated (one-piece) bar and stem or if you want to stash a spare set of wheels in your box. This box ships best domestically; it may be too large for some international shipments.