Professional Speaker 1).ABS Material 2).8~15" active &passive speaker 3).Optional for mono, bi, digital amp with mp3 player: Detailed Product DescriptionProfessional Speaker FS350 FS450Feature:1).ABS Material 2).8"~15" active &passive speaker3).Optional for mono, bi, digital amp with mp3 playerPRODUCTFS350FS450Configuration2-way Active Speaker System2-way Active Speaker SystemFreq Response45Hz- ...