Instructions:

Articulator: Lower Lip

Point of Articulation: Upper Lip

Manner: When the air from the lungs goes over the articulator, which is positioned close to (but not touching) the point of articulation, vibrations occur between the articulator and the point of articulation.

Voice: voiced – Vocal folds are close and vibrating.

Occurrence: Kele, Kom, Komi-Permyak, Medumba, Ngwe (Lebang dialect), Nias, Pará Arárá, Pirahã, Russian, Titan, Ubykh, Unua, Wari’.
(Source: https://en.wikipedia.org/wiki/Bilabial_trill#Occurrence)