... PC 4.ISO 9001:2000 louspeaker Teaching Portable SpeakerFeatures1.speaker sensitivity high2.grinds sand material3.MP3,CD,PC input4 ... .classroon loudspeaker 5.teachers use,classroom speaker,school speaker6.portable,no installation, or wall-mounted1. ... sound quality and complete protection.2. No installation, with speaker bracket.3. Application:classroom, conference room, multi-function hall ...