Usage: fill the mug with liquid and place it on the heating plate; the on/off button activates only when the mug with liquid is placed on the plate (an empty mug may be too light to activate the switch). To stop heating, lift the mug off the plate or consume its contents. The device does not bring liquid to a boil; it heats up to around 55°C (small deviations possible). Coffee should be prepared in another container and then transferred; tea can be brewed directly in this mug. It can heat tea, milk, water, coffee, and liquids in other flat-bottomed containers (cups, boxes, ceramic or metal mugs). Do not use containers with concave contact surfaces; plastic containers are not recommended. Tea & Coffee Machine Accessories