The PE-304BU is an ABS resin bass-reflex enclosure with a 12cm (5") cone-type woofer and a balanced-dome tweeter. These pendant speakers are intended to be installed suspended from a ceiling. They are very lightweight, with a stylish design inspired by modern lighting fixtures, allowing them to harmoniously blend in with a room design. These speakers are ideally suited for applications such as Background Music (BGM) and announcements in high-ceiling venues such as airports, factories and shopping malls, and, in addition, certification to UL 1480 UUMW (Mass Notification System) and ULC-S541 standards enables them to work in emergency announcement systems. The speakers can be driven on both high-impedance (100V, 70V and 25V) and low-impedance (8) lines. Input impedance is adjustable with a rotary switch on the top of the speaker. The hanging wire, safety wire and speaker cable are pre-attached, for quick and easy installation. GRIPPLE® hangers facilitate speaker mounting height adjustment.