Extremely compact size for explosive performance: The ST 25A NEO is the new, updated, and improved sound compression driver from Hertz specifically designed for SPL competitions. 

The NEO bullet line tweets are an entirely new project, lighter and more compact compared to the previous ST 25, and with superior performance thanks to the use of Neodymium N38 H (for the motor units) and the optimized FEM driver/horn design. The "Active" version, ST 25A Neo provides only tweeter.