Keep cables tidy Keep cables neat, improve the look of your classroom & minimise trip hazards with the included cable cover. Easy to use Focus on the lesson rather than your equipment: the ELPCB01 is straightforward to use, with large buttons & clearly-labelled inputs. Outwards-opening doors make accessing the inputs a one-handed job. Extend USB (Universal Serial Bus) cables Extend cables by up to 10 metres with the built-in USB (Universal Serial Bus) signal booster. Simple to install Fix to the wall with just four screws. All inputs & buttons are identical to those on Epson's projectors for easy recognition. Optional speakers Complete your classroom's total audio-visual solution by connecting the two optional Epson 15W speakers with built-in amplifier for powerful sound.