Titanimum Hard Dome Super Tweeter ideal for home speakers or mobile use.Mounts from front or rearPolished aluminum structure.1.7-in Titanimum Hard Dome w/3in center horn.21 Oz Magnet structure 8 Ohm Impedance Sensitivity: 104 dB Freq. Resp.: 2-20 Khz Requires crossover, included Distance between hole centers directly across: 111mmDistance between adjoining hole centers: 79mmRequired minimum mounting rear hole diameter: 109mm.Minimum mounting rear depth: 29mmCenter horn cone diameter: 78mmCenter horn cone depth: 25mmMagnet diamter:109mmOuter flange: 11mmPackage Dimensions: 4.6-in x4.7-in x 3-in500 Watts Power Rated.