Canon's second-generation consumer 75-300mm with USM motor, marginally better than the III.
The Canon EF 75-300mm f/4-5.6 II USM is an early consumer telephoto with a USM motor, launched in the mid-1990s. The USM provides faster and quieter autofocus than the micro-motor III version, but the optical design is essentially the same budget telephoto formula.
Optical quality is similar to the III version — adequate at 75-200mm stopped down but soft above 200mm with visible chromatic aberration. The USM motor is the main advantage over the III, providing faster and quieter AF with full-time manual override.
Canon EF mount, 58mm filter thread. The USM motor makes this marginally more usable than the III for action photography. Both versions are optically poor by modern standards. The EF-S 55-250mm IS STM is vastly better for APS-C users.
Very cheap used. The USM motor is the only real advantage over the even cheaper III. Check USM operation. At these prices the EF-S 55-250mm IS STM is the dramatically better investment.