Megan Pretty much every chastity belt manufacturer makes belts for men, they usually make more male belts than female belts. BehindBarz and Cocoon pretty much exclusively make male belts, Carrara and Latowski make many more male than female belts, the more traditional designs (like MS, NS, TB and all those) are probably a bit more even, but judging by the amount of testimonials on Neosteel's site, male wearers are either a clear majority or far more open about providing feedback.
But many more men wear cages than belts for two reasons. One, they are much cheaper, two, they are usually easier to wear. Belts may get in the way of hip movement, it takes effort to adapt them to weight changes, you often have something around your butt to deal with. Cages go around the genitals and that is it. Of course, belts are more secure, it is harder to shake the penis tube, but between cost and comfort, that security comes at a huge price.
Of course, a drawback of the ring around the genitals is that you might get a bit of a tug on your testicles with a particularly hard erection, but a tug is usually a lot easier to stomach than an impact, the body learns to get milder erections with extended wear (which also happens in a belt that forces the penis down), and the scrotum actually has a fair bit of give in a lot of men. Which is one more reason why belts are more secure.