All our products are available in the following sizes:

alphabox, alphabox 3D pocket, alphabox underwear, alphabox men's underwear, mens underwear, underwear, boxer briefs, boxers
Our Everyday Fit Boxer Briefs in the black and red modal tend to run slightly larger so if you are at the lower end of one size, we suggest you size down and choose the smaller option.
Our Everyday Fit Boxer Briefs in all the other colors fit true to size.
Our Performance Fit Boxer Briefs in the mesh fit true to size.