The Charles Beseler company began in 1868 making scientific and lab equipment, and began producing enlargers in 1953. Beseler is one of the two dominant manufacturers in the USA. Their enlargers (along with Omega) were frequently found in schools and rental labs; a great many students learned how to print on a Beseler enlarger. While not the least expensive, they are typically rugged, no-nonsense machines that are built to last.
Beseler has a naming scheme for most of their enlargers which describes the features of the machine. E.g. a 45MXC is a 4x5 enlarger chassis with a motorized colorhead and extra support truss.