Eminence BH410 1" Exponential Horn 1-3/8"-18 TPI Compact exponentially flared horn for general HF duties. Excellent for bass guitar rigs! Unique flange shape permits extremely close driver spacing while maintaining excellent dispersion characteristics. Recommended for crossover points 1 kHz and higher. Rugged plastic construction. Standard 1-3/8"-18 TPI screw-on mounting.