Candlelight
A candle burns in a dark room. Let your eyes rest on the flame and watch it sway; when thoughts come, notice them and come back to the light. If you like, turn on the breath guide, and the candle's glow will swell as you breathe in and settle as you breathe out.
Look softly, without staring, and blink whenever you need to. You can close your eyes at any time and simply listen. A singing-bowl tone marks the start and the end.
The candle, the room and the sound are all made in code as you watch and listen: no recordings or photographs. Space pauses and carries on.