Complex sentence: In'(TNG) and later series, the crew wear communicator badges (combadges), small devices in the shape of the Starfleet insignia and typically worn on a user's left breast, which are activated with a light tap.
Split into simpler sentences: In' (TNG) and later series, the crew wears small communicator badges on their left breast. These devices are in the shape of the Starfleet insignia, and are activated with a light tap.