The Selenium by JBL ST304 is a super tweeter for outstanding detail and clarity in high-frequencies without harshness. The ST304 may be used individually in lower power systems or arrayed for increased coverage and SPL in higher power systems. The bullet-shape horn design offers a longer throw 40 x 40 degree dispersion. The cast aluminum housing is stable and durable. The phenolic annular diaphragm is long-lasting, cost effective and more natural-sounding than metallic diaphragms. The use of high-temperature materials and adhesives improves power handling and produces exceptionally high acoustic output. A precisely engineered diaphragm structure and alignment mechanism for easy, reliable, cost effective repair in case of diaphragm failure.