Shifter levers on the downtube of your bike frame.

This tag is for old-school shifter levers on the downtube of the frame, approximately straight below your shoulders. They may be friction shifters, or some form of click lever or even indexed, but the shifters must be on the frame not the handlebars, or on your stem.

If you can change gear without moving a hand off the handlebars, then consider another tag instead.