Check the listing for details. MB Acoustics Replacement for Selenium D220Ti Driver 8Ω 1-3/8" Screw-On 550W. Condition: New. Listed at 59.95 USD. You are Buying 1 Compression Driver MB Acoustics MB44, 550W, 1.75" (44mm) Titanium Voice Coil Pro Audio High Frequency Compression Driver for Screw-On Horns Replacement for Selenium D220Ti at a much lower price point. The MB Acoustics MB44 will reproduce High Frequencies. This driver contains a 1.75” Titanium diaphragm matched to a 30oz. magnet to deliver high decibels with even low power amplifiers. Specifications:H.F. Compression Driver for Screw-On Horn (Horn sold separately)Pro Titanium Compression Drivers for Car & Pro AudioRMS Power: 275 WattsMAX Power: 550 WattsVoice Coil size: 1.75" inch (44mm)Diaphragm Material: TitaniumVoice Coil Former: Heat Resistant KaptonImpedance: 8 ohm Gold Spring TerminalsFrequency Response: 1000Hz - 20kHzRecommended crossover: 2kHz, 12dB/octaveSensitivity: 103dB 1W/1mMagnet Structure Weight: 30 oz. Easy Diaphragm ReplacementMagnet Diameter: 4.5" / 115mmOverall Height: 2.5" / 64mmThread Diameter: 1-3/8" (35mm) - 18 TPIDriver Weight: 3.2 lbs.