Canon's cheapest telephoto — notoriously soft with no IS, no USM, DC motor — widely considered their worst lens.
The Canon EF 75-300mm f/4-5.6 (1991) is the original version of Canon's budget telephoto range — the cheapest Canon lens with a DC motor, no USM, no stabilisation, and plastic construction. It is widely considered Canon's worst telephoto zoom.
Notoriously soft at all focal lengths. Low contrast. Visible chromatic aberration. DC motor AF is slow and noisy. 5-blade aperture produces harsh bokeh. 150cm minimum focus distance.
Canon EF mount, 58mm filter thread. Full-frame. 480g. Plastic mount. No filter rotation during focus. Mark II and III versions exist with minor improvements but remain optically poor.
Extremely common and nearly worthless — often under £15 used. Avoid unless bundled free with a body. The 55-250mm IS STM or 70-300mm IS II USM are vastly superior alternatives.