PROTM SERIES PORTABLE GENSETS Onan ProTM Series Portable GenSets are quality-built to handle tough commercial jobs. Designed for rigorous use, they feature overhead valve engines for quiet operation and fuel conservation, extra-large fuel tanks, simultaneous AC/DC power, automatic oil-level shut-down, and GFCI circuit breakers. Dolly kits are available. Choose from 3 models, ranging from 4000 to 6000 watts, 50/60 Hz.