The sensor is about 6.6 cm x 2.3 cm. It is worn vaginally during the night and reliably measures your body’s core temperature.

When worn, the sensor sits like a tampon in the middle part of the vagina. Here are only a few sensory nerves compared to the outer part of the vulva, which is why the trackle is not noticeable for most users. Your pelvic floor and vaginal muscles keep the sensor in the right position and prevent it from slipping.

By the way, you don't have to worry about the sensor disappearing inside you, because this is anatomically impossible: it can't get past the cervix.